Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.mseb.2023.116579

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.cgd.2c01537

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.cartre.2023.100246

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsabm.2c01033

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.jpcb.2c06329

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：International Union of Crystallography (IUCr)  

The double-crystal configuration is useful for the evaluation of strain and defects in single crystals. In this study, rocking curve measurements by X-ray topography in the double-crystal configuration were demonstrated using perfect crystals of the protein glucose isomerase (GI). The setup enables precise evaluation of perfection in protein crystals with the nearly nondispersive X-ray optics. It reveals the uniform perfection of GI crystals according to the theory of X-ray diffraction. It is expected that unknown imperfections in various protein crystals of lower quality will be revealed by the nondispersive configuration using perfect protein crystals.

DOI： 10.1107/s1600576722007130

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.cplett.2022.140094

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Society of Materials Science, Japan  

DOI： 10.2472/jsms.71.749

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Proceedings of the National Academy of Sciences  

Significance

Growing high-quality protein crystals is a prerequisite for the structure analysis of proteins by X-ray diffraction. However, dislocation-free perfect protein crystals such as silicon and diamond are limited to two kinds of protein crystals. We wonder whether other high-quality or dislocation-free protein crystals still exhibit some imperfection. Here, we explore the existence of twisting as a cause of imperfection in high-quality protein crystals by X-ray topography with synchrotron radiation. The magnitude of twisting is quite small and cannot be detected by conventional techniques as optical and electron microscopy. The formation of twisting may be related to the geometric frustration mechanism proposed as a primary mechanism of twisting. This finding provides insights on high-quality protein crystals with the ubiquity of twisting.

DOI： 10.1073/pnas.2120846119

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：International Union of Crystallography (IUCr)  

The characterization of crystal defects induced by irradiation, such as X-rays, charged particles and neutrons, is important for understanding radiation damage and the associated generation of defects. Radiation damage to protein crystals has been measured using various methods. Until now, these methods have focused on decreased diffraction intensity, volume expansion of unit cells and specific damage to side chains. Here, the direct observation of specific crystal defects, such as dislocations, induced by X-ray irradiation of protein crystals at room temperature is reported. Dislocations are induced even by low absorbed doses of X-ray irradiation. This study revealed that for the same total absorbed dose, the formation of defects appears to critically depend on the dose rate. The relationship between dislocation energy and dose energy was analyzed based on dislocation theory associated with elasticity theory for crystalline materials. This demonstration of the crystal defects induced by X-ray irradiation could help to understand the underlying mechanisms of X-ray-induced radiation damage.

DOI： 10.1107/s205979832101281x

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

We report two organic crystals of 2,2′:6′,2′′-terpyridine derivatives each substituted with luminescent naphthyl and anthryl moieties, displaying multi-faceted flexible bending with elasticity in response to mechanical stress.

DOI： 10.1039/d2ce01167k

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

A long alkyl-chained organic molecule has been crystallized into elastically or plastically deformable bending types depending on the recrystallization solvent.

DOI： 10.1039/d2cc00663d

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsanm.1c02977

researchmap

DOI： 10.19009/jjacg.48-2-02

researchmap

Publishing type：Research paper (scientific journal)   Publisher：International Union of Crystallography (IUCr)  

It is important to reveal the exact cause of poor diffractivity in protein crystals in order to determine the accurate structure of protein molecules. It is shown that there is a large amount of local strain in subgrains of glucose isomerase crystals even though the overall crystal quality is rather high, as shown by clear equal-thickness fringes in X-ray topography. Thus, a large stress is exerted on the subgrains of protein crystals, which could significantly lower the resistance of the crystals to radiation damage. It is also demonstrated that this local strain can be reduced through the introduction of dislocations in the crystal. This suggests that the introduction of dislocations in protein crystals can be effective in enhancing the crystal quality of subgrains of protein crystals. By exploiting this effect, the radiation damage in subgrains could be decreased, leading to the collection of X-ray diffraction data sets with high diffractivity.

DOI： 10.1107/s2059798321001820

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Union of Crystallography (IUCr)  

X-ray topography is a useful and nondestructive method for direct observation of crystal defects in nearly perfect single crystals. The grown-in dislocations from the cross-linked seed crystal in tetragonal hen egg-white lysozyme crystals were successfully characterized by digital X-ray topography. Digital X-ray topographs with various reflections were easily obtained by reconstruction of sequential rocking-curve images. The Burgers vector of the dislocation is different from those reported previously. Interestingly, one of the dislocations had a bent shape. The preferred direction of the dislocation line was analysed by the estimated dislocation energy based on the dislocation theory. The dislocation energy can be estimated by the dislocation theory even in protein crystals composed of macromolecules.

DOI： 10.1107/s1600576720015356

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

Abstract

We report a fabrication process of TiO₂ nanowall (NW) structures using carbon nanowall (CNW) templates. Ti-contained CNW templates were synthesized by plasma-enhanced chemical vapor deposition and sputtering (Ti-target) hybrid system. TiO₂ NW structures were then obtained by annealing of the Ti-contained CNW template, which was additionally coated by Ti sputtering, in air. The NW structure could not be retained after annealing of Ti-contained CNW templates without the additional Ti coatings because the amount of Ti in Ti-contained CNWs was not enough to maintain the NW. Using TiO₂ NW as a photoanode for water splitting, the photo-response was confirmed by photoelectrochemical measurements.

DOI： 10.35848/1347-4065/abcffb

researchmap

Other Link： https://iopscience.iop.org/article/10.35848/1347-4065/abcffb/pdf

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

<p>Slip systems in triclinic hen egg-white lysozyme (Tri-HEWL) crystals, which is one of typical protein crystals, were identified by the indentation method and the surface energy estimation using phenomenological macro-bond methods.</p>

DOI： 10.1039/d1ce00241d

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/s41598-020-69264-9

researchmap

Other Link： http://www.nature.com/articles/s41598-020-69264-9

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.carbon.2020.07.027

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.diamond.2020.108047

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.carbon.2020.07.061

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：International Union of Crystallography (IUCr)  

Knowledge of X-ray diffraction in macromolecular crystals is important for not only structural analysis of proteins but also diffraction physics. Dynamical diffraction provides evidence of perfect crystals. Until now, clear dynamical diffraction in protein crystals has only been observed in glucose isomerase crystals. We wondered whether there were other protein crystals with high quality that exhibit dynamical diffraction. Here we report the observation of dynamical diffraction in thin ferritin crystals by rocking-curve measurement and imaging techniques such as X-ray topography. It is generally known that in the case of thin crystals it is difficult to distinguish whether dynamical diffraction occurs from only rocking-curve profiles. Therefore, our results clarified that dynamical diffraction occurs in thin protein crystals because fringe contrasts similar to <italic>Pendellösung</italic> fringes were clearly observed in the X-ray topographic images. For macromolecular crystallography, it is hard to obtain large crystals because they are difficult to crystallize. For thin crystals, dynamical diffraction can be demonstrated by analysis of the equal-thickness fringes observed by X-ray topography.

DOI： 10.1107/s2052252520007393

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41598-019-50397-5

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.diamond.2019.107602

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.electacta.2019.03.088

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

We report a synthetic technique for the preparation of α-Fe2O3 nanowall (NW) structures using carbon nanowalls (CNWs) as templates. The insertion of Fe atoms inside the CNWs is achieved by the simultaneous sputtering of the Fe target during CNW growth by plasma-enhanced chemical vapor deposition. By annealing of Fe-inserted CNWs at 500 °C-700 °C in air, the C is oxidized and desorbs as CO2, during which the Fe is sintered and NW structures are maintained. Consequently, the desired α-Fe2O3 NWs are obtained. SEM observation reveals that the α-Fe2O3 NW consisted of nanoparticle chains with diameters of approximately 40 to 50 nm upon increasing the annealing temperature from 500 °C to 700 °C. SiO2 (α-quartz) NWs are also formed using similar processes through the appropriate choice of sputtering target. These results demonstrate the possibility of controlling the composing atom of oxide NW structures using universal processes and conditions.

DOI： 10.7567/1347-4065/ab37fe

Scopus

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cplett.2019.05.047

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.cgd.9b01084

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：National Academy of Sciences  

High-quality protein crystals meant for structural analysis by X-ray diffraction have been grown by various methods. The observation of dynamical diffraction in protein crystals is an interesting topic because dynamical diffraction generally occurs in perfect crystals such as Si crystals. However, to our knowledge, there is no report yet on protein crystals showing clear dynamical diffraction. We wonder whether the perfection of protein crystals might still be low compared with that of high-quality Si crystals. Here, we present observations of the oscillatory profile of rocking curves for protein crystals such as glucose isomerase crystals. The oscillatory profiles are in good agreement with those predicted by the dynamical theory of diffraction. We demonstrate that dynamical diffraction occurs even in protein crystals. This suggests the possibility of the use of dynamical diffraction for the determination of the structure and charge density of proteins.

DOI： 10.1073/pnas.1720098115

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.cgd.8b00798

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.actamat.2018.06.018

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The relationship between protein crystal quality and growth kinetics was assessed by measuring the normal growth rates vs supersaturation of the (110) and (101) faces of dislocation-free tetragonal hen egg white lysozyme crystals at three precipitant concentrations, with NaCl as the precipitant. Assuming a two-dimensional birth and spreading nucleation mechanism, an increase in the surface free energy of the step edges was realized with increasing NaCl concentration, as established by decreases in the full width at half maximum values of X-ray diffraction rocking curves obtained from crystals. These results demonstrate that controlling the surface free energy of the step edges is an important aspect of obtaining high-quality protein crystals. This work also proposes a mechanism for the observed improvements in the crystal quality, based on the reduced incorporation of impurities into the steps during crystal growth.

DOI： 10.1021/acs.cgd.7b01315

Web of Science

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Vickers microindentation hardness of protein crystals was investigated on the (110) habit plane of tetragonal hen egg-white lysozyme crystals containing intracrystalline water at controlled relative humidity. The time evolution of the hardness of the crystals exposed to air with different humidities exhibits three stages such as the incubation, transition, and saturation stages. The hardness in the incubation stage keeps a constant value of 16 MPa, which is independent of the humidity. The incubation hardness can correspond to the intrinsic one in the wet condition. The increase of the hardness in the transition and saturation stages is well fitted with the single exponential curve, and is correlated with the reduction of water content in the crystal by the evaporation. The saturated maximum hardness also strongly depends on the water content equilibrated with the humidity. The slip traces corresponding to the 1 (1) over bar0 [110] slip system around the indentation marks are observed in not only incubation but also saturation stages. It is suggested that the plastic deformation in protein crystals by the indentation can be attributed to dislocation multiplication and motion inducing the slip. The indentation hardness in protein crystals is discussed in light of dislocation mechanism with Peierls stress and intracrystalline water.

DOI： 10.3390/cryst7110339

Web of Science

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

A hybrid plasma-enhanced chemical vapor deposition (PECVD)/sputtering system was developed to prepare iron (Fe)-nitrogen (N)-doped carbon catalysts for oxygen reduction reaction (ORR). This hybrid system combines PECVD effective for the synthesis of nanocarbons with sputtering technique for the doping of metals such as Fe where the amount of the doping can be independently controlled during synthesizing nanocarbons. By using this system, Fe-N-doped carbon catalysts are directly synthesized on carbon papers which have been widely used as a gas diffusion layer in fuel cells. The synthesized catalysts with carbon papers exhibit high ORR activity. This is attributed to Fe-N coordination bonds which are stably formed in the synthesized catalysts. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2017.04.085

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

High quality glucose isomerase (GI) single crystals are grown by using chemical cross-linked seed crystals. The crystal structure is an orthorhombic system in which the molecular arrangement is close to a body-centered cubic (bcc) one. The crystal defects, especially dislocations, in GI crystals are experimentally characterized by synchrotron monochromatic-beam X-ray topography. Two straight dislocations are clearly observed, which originate from the interface between the cross-linked seed crystal and the grown crystal. From the invisibility criterion of the dislocation images, it is experimentally identified that they are close to be of pure edge character with the Burgers vector of [1 1 1] which is typical one in bcc metal crystals. Moreover, bead-like contrasts along the dislocation images and the equal-thickness fringes, related to Pendellosung fringes, at crystal edges are clearly observed, which have never been observed in other protein crystals so far. These contrasts can attributed to the dynamical diffraction effect which has been often observed in high-quality crystals such as Si. Thus it seems that the perfection of GI crystals shown in this paper is extremely high compared with other protein crystals reported so far.

DOI： 10.1016/j.jcrysgro.2016.10.047

Web of Science

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.72.2.0_2350

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Large single crystals with desirable shapes are essential for various scientific and industrial fields, such as X-ray/neutron crystallography and crystalline devices. However, in the case of proteins the production of such crystals is particularly challenging, despite the efforts devoted to optimization of the environmental, chemical and physical parameters. Here we report an innovative approach for promoting the growth of protein crystals by directly modifying the local crystal structure via femtosecond laser ablation. We demonstrate that protein crystals with surfaces that are locally etched (several micrometers in diameter) by femtosecond laser ablation show enhanced growth rates without losing crystal quality. Optical phase-sensitive microscopy and X-ray topography imaging techniques reveal that the local etching induces spiral growth, which is energetically advantageous compared with the spontaneous two-dimensional nucleation growth mode. These findings prove that femtosecond laser ablation can actively switch the crystal growth mode, offering flexible control over the size and shape of protein crystals.

DOI： 10.1038/NPHOTON.2016.202

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We developed a protein crystallization technique using a 0.0-2.0 w/v% agarose gel solution combined with a stirring technique for the purpose of controlling the crystal number in the gelled solutions. To confirm the stirring effect in the gelled solution, we investigated the nucleation probability and growth rate of the crystals produced using this method. The stirring operation by a rotary shaker affected the behavior of protein molecules in the gelled solution, and both a significant decrease in the nucleation rate and an enhancement of the crystal growth rate were achieved by the method. As a result, we concluded that the proposed technique, the stirring technique in a gel solution, was effective for generating protein crystals of sufficient and increased mechanical stability. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2015.11.008

Web of Science

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Single-layer-graphene-like nanocarbon materials were directly deposited on c-plane sapphire substrates by thermal chemical vapor deposition with ethanol as a carbon source. Scanning electron microscopy (SEM) images show that the deposited materials have sheetlike grains of around 100 nm diameter. Most of them have "hills" with 32nm diameter on the grains. According to atomic force microscopy (AFM) observation, the height of the sheetlike grains is below 1 nm, which is comparable to that of single-layer graphene, while the hills have a height of several nm. Raman spectra show that the material is similar to graphitic nanocarbon, which has a strong D band. This result implies that there are a number of defects in the nanocarbon materials. (C) 2016 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.55.105101

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

In this, study, we show using X-ray diffraction (XRD) rocking-curve measurements that 1 01 strain in tetragonal hen egg white (HEW) lysozyme crystals can be removed to a large degree by utilizing seed crystals cross-linked with glutaraldehyde. We, also find that misorientation between subgrains and subgrain size decrease when employing cross-linked seed crystals, which suggests that subgrain formation in tetragonal HEW lysozyme crystals can be controlled using this technique. The ideal mosaic structure of proteins that enables the: collection of accurate integrated intensities of the diffracted waves is also discussed using tetragonal HEW lysozyme crystals as a model protein.

DOI： 10.1021/acs.cgd.6b01136

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

In this study, pressure-induced transformation in ferrocene (Fc)-doped C-60 nanosheets containing alternating layers of C-60 and Fc is investigated using in situ Raman spectroscopy. In particular, the change in the A(g)(2) mode of C-60, which is very sensitive to the state of C-60 in the crystals, is examined at pressures up to 12.5 GPa. Orientational ordering and polymerization, mainly one-dimensional (1D) polymerization, in the C-60 layers are observed with increasing pressure. High pressure can also lead to the formation of higher-order polymers, such as two-dimensional or branched 1D polymers, similar to parts of molecular arrangement in C-60 layers. Such transformations are reversible with pressure. Notably, pressure-induced polymerization, mainly 1D polymerization, is promoted and stabilized by light irradiation. In addition, under high pressure, higher-order polymers can be broken and reformed as stabilized 1D polymers via light irradiation. Under pressure, photo-induced 1D polymerization is irreversible. Thus, light irradiation can allow more stable polymers or 1D photo-polymers even under high pressure. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2016.06.042

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We show that the extinction effect explained by the dynamical theory of diffraction must be considered even in the case of protein crystals. Equal-thickness fringes, which are attributed to the Pendellosung effect, were clearly observed in the region of a tapered glucose isomerase crystal with wedge-like edges using X-ray topography carried out with a beam of monochromatic synchrotron radiation. This indicates that the perfection of this glucose isomerase crystal is high enough to produce this dynamical theory-related effect: this surely leads to difficulty in the collection of accurate integrated intensities of diffraction spots for Xray structural analysis. Therefore, it is important to determine whether the crystal quality of a protein crystal under analysis is adequate to obtain accurate three-dimensional structures of protein molecules for X-ray structural analyses. We show that X-ray diffraction rocking-curve measurements can provide clues for this determination.

DOI： 10.1021/acs.cgd.6b00457

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

X-ray diffraction (XRD) rocking-curves were measured for tetragonal hen egg white (HEW) lysozyme crystals grown with and without application of an external electric field, and the crystal quality was assessed according to the full width at half-maximums (FWHMs) of each rocking-curve profile. The average FWHMs for tetragonal HEW lysozyme crystals grown with an external electric field at 1 MHz were smaller than those for crystals grown without, especially for the 12 12 0 reflection. The crystal homogeneity of the tetragonal HEW lysozyme crystals was also improved under application of an external electric field at 1 MHz, compared to that without. Improvement of the crystal quality of tetragonal HEW lysozyme crystals grown under an applied field is discussed with a focus on subgrain formation. In addition, the origin of subgrain misorientation is also discussed with respect to the incorporation of impurities into protein crystals.

DOI： 10.3390/cryst6080095

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Hardness and slip systems by an indentation method were investigated on different habit planes of orthorhombic hen egg-white lysozyme (O-HEWL) crystals containing water. A dependence of the hardness on the water-evaporation time exhibits three stages as incubation, transition and saturated ones, as tetragonal (T)-HEWL crystals reported previously. The hardness values of (110), (010) and (011) habit planes of O-HEWL in the incubation stage or wet condition exhibits 6, 8 and 10MPa, respectively. The hardness depends on indented planes but it is independent of the air-humidity and crystal volumes. These values correspond to the intrinsic hardness for O-HEWL crystals containing water. In the incubation stage, the slip traces are clearly observed around the indentation mark and the corresponding six kinds of slip systems are identified to be {011}&lt;100&gt;, {110}&lt;110&gt;, {011}&lt;011&gt;, {110}&lt;001&gt;, {100}&lt;001&gt; and {010}&lt;001&gt;.

DOI： 10.1080/14786435.2016.1219074

Web of Science

researchmap

Language：English   Publisher：The Materials Research Society of Japan  

Ferrocene-doped C₆₀ nanosheets consisting of alternating C₆₀ and ferrocene layers were grown by liquid-liquid interfacial precipitation method, and their pressure-induced transformation at room temperature was investigated by means of Raman spectroscopy. The charge transfer and polymerization of C₆₀ occur with increasing pressure even at room temperature, while the transition pressures are low compared with those of the same kind of sample reported previously. The discrepancy in the transition pressures can be attributed to the crystal quality. In addition, it should be noted that the structure of the sample recovered after decompression is found to be amorphous C₆₀, although the Raman spectrum almost completely returns to the starting one of isolated C₆₀. Such depolymerization of C₆₀ would be due to the effect of ferrocene layers which stabilize the initial isolated C₆₀ at ambient temperature and pressure.

DOI： 10.14723/tmrsj.41.71

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.diamond.2015.10.027

Scopus

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.71.2.0_2519

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.71.2.0_2448

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.71.2.0_1559

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Society of Computer Chemistry Japan  

DOI： 10.2477/jccj.2016-0016

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Carbon nanowalls (CNWs) with different domain sizes were synthesized by a dc plasma-enhanced chemical vapor deposition. Platinum (Pt) loading on the CNWs (Pt/CNW) was carried out by a solution reduction method. As a result, Pt nanoparticles were preferentially deposited along the domain boundaries in CNWs as reported previously. It should be noted that the Pt particle size strongly depends on the domain size. Namely, the smaller the domain size is, the smaller the Pt particle size is. Moreover, the Pt/CNW with smaller Pt particles exhibit high catalytic activity. Especially, the mass activity related to cathodic oxygen reduction reaction (ORR) is high and reach about five times as much as that of commercial T-Pt/CB with good performance. The high ORR activity can be attributed to the domain boundaries in CNWs, which might lower not only the activation energy of O-2 dissociation on Pt particles but also the energy barrier of the rate-limiting step in the ORR process. (C) 2015 AIP Publishing LLC.

DOI： 10.1063/1.4936787

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：INT UNION CRYSTALLOGRAPHY  

The effect of a 20 kHz external electric field on the quality of tetragonal hen egg white (HEW) lysozyme crystals was investigated using X-ray diffraction rocking-curve measurements. The full width at half-maximum was found to be larger for high-order reflections but smaller for low-order reflections. In particular, it was revealed that a large amount of local strain is accumulated in tetragonal HEW lysozyme crystals grown under an applied field at 20 kHz. Comparison with previous results obtained for crystals grown with an applied field at 1 MHz [Koizumi, Uda, Fujiwara, Tachibana, Kojima & Nozawa (2013). J. Appl. Cryst. 46, 25-29] indicated that improvement of the protein crystal quality could be achieved by selection of an appropriate frequency for the applied electric field, which has a significant effect on the growth of the solid.

DOI： 10.1107/S1600576715015885

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：EDP Sciences  

DOI： 10.1051/metrology/20150014004

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The normal growth rates of the {110} faces of tetragonal hen egg-white lysozyme crystals, R, were measured as a function of the supersaturation sigma parameter using a reflection type interferometer under mu G at the International Space Station (NanoStep Project). Since water slightly evaporated from in situ observation cells during a long-term space station experiment for several months, equilibrium temperature T-e changed, and the actual sigma, however, significantly increased mainly due to the increase in salt concentration C-s. To correct sigma, the actual C-s and protein concentration C-p, which correctly represent the measured T-e value in space, were first calculated. Second, a new solubility curve with the corrected C-s was plotted. Finally, the revised sigma was obtained from the new solubility curve. This correction method successfully revealed that the 2.8% water was evaporated from the solution, leading to 2.8% increase in the C-s and C-p of the solution. (C) 2015 AIP Publishing LLC.

DOI： 10.1063/1.4928491

Web of Science

researchmap

DOI： 10.14723/tmrsj.40.417

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

DOI： 10.11316/jpsgaiyo.70.2.0_2442

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

DOI： 10.11316/jpsgaiyo.70.1.0_2680

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

DOI： 10.11316/jpsgaiyo.70.1.0_2679

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

DOI： 10.11316/jpsgaiyo.70.1.0_3409

CiNii Books

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. Analysis of the full width at half-maximum (fwhm) of the rocking curves indicated that misorientation between subgrains, |theta - theta|, and local strain, &lt;epsilon&gt;, in the crystals contributed to the broadening of the experimentally determined rocking curves for the tetragonal HEW lysozyme crystals. In particular, the data suggested that imperfections in tetragonal HEW lysozyme crystals are predominantly caused by misorientation between subgrains. Moreover, it was determined that improvements in the quality of tetragonal HEW lysozyme crystals, as assessed by a decrease in the misorientation between subgrains, can be achieved by imposing a 1 MHz electric field during crystal growth. This paper also discusses the origin of subgrain misorientation in light of the incorporation of impurities into protein crystals.

DOI： 10.1021/cg500946b

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Glucose isomerase crystals with thicknesses of 0.5 mm were grown using seed crystals. The thickness required for better X-ray topographic images by kinematical theory is determined by the extinction distance, xi(g). The seed crystals were cross-linked with glutaraldehyde to maintain stability for a long period before the growth experiments. Dislocations that were produced during the growth of such thick glucose isomerase crystals were observed as clearly as those in inorganic crystals via X-ray topography with monochromatic-beam synchrotron radiation, which is attributed to the high quality of the glucose isomerase crystals. This also indicates that high-quality protein crystals can be grown using seed crystals. The dislocations extended from the interface with the cross-linked seed crystal to the surface of the grown crystal; however, no dislocations were generated if the seed crystal was not cross-linked. We discuss the effect of the chemical cross-linking of the seed on the generation of dislocations from seed crystals.

DOI： 10.1021/cg500731v

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

C-70 two-dimensional nanosheets were first synthesized by a liquid liquid interfacial precipitation method with isopropyl alcohol and Cm-saturated toluene adding terrocene. The typical C-70 nanosheets have hexagonal shapes with similar to 4.6 ti M in size and similar to 350 nm in thickness. The structure shows a monoclinic one identical to C-70(ferrocene)(2) bulk crystals grown from a solution with ferrocene reported previously. The monoclinic C-70 nanosheets are converted to fcc ones by the evaporation of the ferrocene due to the heat-treatment, whereas the hexagonal shape and size remain almost unchanged. (C) 2014 Elsevier B.V. All rights reserved

DOI： 10.1016/j.jcrysgro.2013.12.056

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The crystal distortion of monoclinic hen egg-white lysozyme (HEWL) crystals was observed by the X-ray digital topography. The local rocking curves were obtained by the series of the topographic images. The single, double, triple, and multiple peaks of the local rocking curves were observed. The mapping of the full width of the one tenth maximum (FW10M) of the local rocking curves was obtained, It was found that the magnitude of FW1OM depended on the distance of the peak splitting. The distribution of the distortion in the monoclinic HEWL crystals was investigated by the analysis of the local rocking curves. (C) 2014 Elsevier BY. All rights reserved.

DOI： 10.1016/j.jcrysgro.2013.12.036

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The temperature dependence of the Raman spectra in the temperature range between 298 and 673K was investigated for polycrystalline monolayer graphene films with defects, such as domain boundaries, synthesized by chemical vapor deposition. The Raman frequencies of G and 2D bands monotonically decrease with increasing temperature. The reversible change in the band frequencies is observed during thermal cycling after the first heating. From the reversible change, the temperature coefficients of G and 2D band frequencies are estimated to be -0.024 and -0.043 cm(-1)/K, respectively. These values are small compared with those for mechanically exfoliated ones without defect reported previously. Furthermore, the magnitude of the temperature coefficient of the G band decreases with increasing defect density. The smaller temperature coefficients can be explained by the suppression of anharmonic phonon interactions due to the defects. (C) 2014 AIP Publishing LLC.

DOI： 10.1063/1.4890388

Web of Science

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publisher：Jenny Stanford Publishing  

DOI： 10.1201/b15656

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSICAL SOC  

The ultrasonic sound velocities of cross-linked orthorhombic hen egg-white lysozyme (HEWL) crystals, including a large amount of water in the crystal, were measured using an ultrasonic pulse-echo method. As a result, seven elastic constants of orthorhombic crystals were observed to be C-11 = 5.24 GPa, C-22 = 4.87 GPa, C-12 = 4.02 GPa, C-33 = 5.23 GPa, C-44 = 0.30 GPa, C-55 = 0.40 GPa, and C-66 = 0.43 GPa, respectively. However, C-13 and C-23 could not be observed because the suitable crystal planes could not be cut from bulk crystals. We conclude that the observed elastic constants of the cross-linked crystals are coincident with those of the intrinsic crystals without cross-linking. Moreover, the characteristics of the elastic constants in orthorhombic HEWL crystals are due to the fact that the shear elastic constants, C-44, C-55, and C-66, are softer than in tetragonal crystals. That is, the shear components, C-44, C-55, and C-66, are one half of those of the tetragonal crystals.

DOI： 10.1103/PhysRevE.89.012714

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jcrysgro.2013.11.009

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER INST PHYSICS  

X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. The crystal quality was assessed by the full width at half maximum (FWHM) value for each rocking curve. For two-dimensional maps of the FWHMs measured on the 440 and the 12 12 0 reflection, the crystal homogeneity was improved under application of an external electric field at 1 MHz, compared with that without. In particular, the significant improvement of the crystal homogeneity was observed for the 12 12 0 reflection.

DOI： 10.1063/1.4897724

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The growth rate vs. supersaturation of a lysozyme crystal was successfully measured in situ together with the crystal surface observation and the concentration measurements onboard the International Space Station. A Michelson-type interferometer and a Mach-Zehnder interferometer were, respectively, employed for real-time growth rate measurements and concentration field measurements. The hardware development, sample preparation, operation, and analysis methods are described. (C) 2013 AIP Publishing LLC.

DOI： 10.1063/1.4826090

Web of Science

J-GLOBAL

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white lysozyme (HEWL) crystals grown with and without application of an external alternating current (AC) electric field, and then the crystal quality was assessed by the FWHMs of each rocking-curve profile. The FWHMs for HEWL crystals grown with an external electric field were smaller than those for crystals grown without. In particular, the average FWHM for the 12 12 0 reflection with an external electric field (0.0034 degrees) was significantly smaller than that without (0.0061 degrees). This indicates that the crystal quality of HEWL crystals was improved by application of the external AC electric field. This crystallization technique can be expected to enhance the resolution of protein molecule structure analysis by X-ray diffraction.

DOI： 10.1107/S0021889812048716

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Here, we report the synthesis of transparent graphitic tiles from carbon nanowalls (CNWs) by shock compression and rapid quenching. The transparent tiles are included in samples recovered from shock pressures above 57 GPa. They exhibit strong photoluminescence but no diamond Raman peak, similar to the case of amorphous diamond synthesized from C60 fullerene and neutron-irradiated graphite. However, the electron energy-loss spectroscopy exhibits relatively intense π* peak associated with graphite, that is inconsistent with the transparency. From these results, it is suggested that the transparent tile is a mixture of amorphous diamond and superhard graphitic material with the transparency. Such carbon phase may come from the unique structural feature of CNWs as the starting material for the shock compression. © 2013 American Institute of Physics.

DOI： 10.1063/1.4789609

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Materials Research Society of Japan  

Structure of the C₆₀ nanowhiskers (C₆₀NWs) heat-treated at high temperatures was investigated by high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), Raman spectrometry, thermogravimetric analysis, Brunauer-Emmett-Teller (BET) method, and so forth. Although the C₆₀NWs heated at 800 °C in vacuum showed a remaining of C₆₀ molecules, the C₆₀NWs became amorphous by heating at 900 °C in vacuum, exhibiting the highest specific surface area of 195.2 m²g^-1.The porous nanofibers synthesized by heating C₆₀NWsat high temperatures are new candidates of superconductive graphitic carbon.

DOI： 10.14723/tmrsj.38.517

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Materials Research Society of Japan  

The effect of laser irradiation on few-layer graphene in air was investigated by Raman spectroscopy. The irradiation results in an increase of D band intensity and a concomitant drop in 2D band intensity. Furthermore, both frequencies of G and 2D bands increase. For bilayer and trilayer graphenes, the shape of the 2D band is also changed after the irradiation. Namely, the high-frequency components decrease. From these results, it is suggested that the laser irradiation in air leads to the thermal oxidation with the hole doping and the change in the stacking sequence in the decomposed few-layer graphene with smaller size.

DOI： 10.14723/tmrsj.38.579

researchmap

DOI： 10.19009/jjacg.40.2_126

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Digital X-ray topography using an X-ray CCD camera and conventional X-ray topography using X-ray film were used to investigate tetragonal hen egg-white lysozyme (HEWL) crystals. Previously, clear dislocation images of protein crystals were mainly obtained by film methods. Earlier studies of HEWL crystals using an X-ray CCD camera mainly revealed domain structures. In the present study, dislocation images of the same HEWL crystal have been obtained by using conventional X-ray film and a digital X-ray CCD camera. The results demonstrate that digital topography using an X-ray CCD camera is an effective method for characterizing protein crystals. A series of digital topographic images were analyzed by the method developed by Lovelace, Murphy, Pahl, Brister & Borgstahl [J. Appl. Cryst. (2006), 39, 425432]. Sub-peaks and peak broadening originating from dislocations in local rocking curves were observed. Moreover, the crystal perfection was evaluated by mapping the angular positions of the maximums and the full widths at half-maximum of local rocking curves.

DOI： 10.1107/S0021889812032049

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The early stage of carbon nanowall (CNW) growth on Si substrate by dc plasma-enhanced chemical vapor deposition (PECVD) was investigated by means of atomic force microscopy and Raman spectroscopy. First nanodiamond particles with highly defective graphene layers are shown to be formed over the substrate. Subsequently nanographite grains are formed on the nanodiamond film. The density of nanographite grains increases with increasing deposition time, and they coalesce to form a continuous graphite film. Finally CNWs are shown to grow vertically on the graphite film. Such understanding of the interface layers between the substrate and CNWs will be useful for not only the growth control but also device applications. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2012.02.026

Web of Science

researchmap

Language：Japanese   Publisher：The Crystallographic Society of Japan  

X-ray topography, especially synchrotron X-ray topography, provides a useful tool for the characterization of protein crystals in order to characterize the defects. We observed clear images of dislocations in hen-egg white lysozyme crystals. In this article we overviewed the research on crystal defects, especially dislocations of protein crystals by synchrotron X-ray topography.

DOI： 10.5940/jcrsj.54.29

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/10000042641?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Platinum catalysts supported on carbon nanowalls (Pt/CNW) were prepared by a solution-reduction method. It is shown that Pt nanoparticles with a mean diameter of 3.5 nm are well dispersed along domain boundaries in each CNW. In addition, it is shown that the Pt/CNW has high electrochemical active surface area and utilization, comparable to those for commercially available T-Pt/CB with good performance. Such high electrocatalytic activity could be attributed to the high electric conductivity of CNW and the improvement of electronic properties of Pt nanoparticles on the domain boundaries, in addition to the high dispersion of Pt particles. (C) 2011 American Institute of Physics. [doi:10.1063/1.3662142]

DOI： 10.1063/1.3662142

Web of Science

researchmap

Language：English   Publishing type：Part of collection (book)   Publisher：Pan Stanford Publishing Pte. Ltd.  

C60 nanowhiskers (C60NWs) are obtained from the solution growth by using a liquid-liquid interfacial precipitation method. The growth of C60NWs is promoted by light illumination. Typical C60NWs are less than 500 nm in diameter and greater than 100 μm in length. As-grown C60NWs in the solution have a hexagonal solvated structure. The structure is easily changed into a face-centered cubic (fcc) one by the evaporation of solvent molecules in air. The solvated structures exhibit large elastic deformation. Compared with the solvated structures, the fcc structures in air show small elastic deformation, i.e., relative brittleness,. The fcc structures also exhibit semiconductor properties as do intrinsic fcc C60 bulk crystals. Such unique shapes and novel properties of C60NWs are very attractive for various applications in the fields of nanoscale devices, energy, and environment. In this chapter, the growth method and structural characteristics for C60NWs are reviewed. In addition, the mechanical properties related to the structures are shown. © 2012 Pan Stanford Publishing Pte. Ltd. All rights reserved.

DOI： 10.4032/9789814241632

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We report the formation of trans-polyacetylene from single-wall carbon nanotubes (SWCNTs). The SWCNTs including metal catalysts were exposed to air with water vapor for a long time, and then irradiated with laser light. The formation of trans-polyacetylene in the irradiated SWCNTs was observed by means of Raman spectroscopy. The formation process can be related to the cutting of SWCNTs due to the catalytic hydrogenation by laser heating. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2011.01.009

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Dislocations in monoclinic hen egg-white lysozyme crystals were investigated by means of synchrotron monochromatic-beam X-ray topography. The loop and curved dislocations were observed to be predominant in the crystals. Almost all the dislocations lay in (1 0 (1) over bar) crystallographic plane, which corresponds to that with smallest slicing energy estimated by macrobond approach. One of the Burgers vectors of the dislocations was determined to be [0 1 0], which corresponds to the smallest lattice translational vector on the (1 0 (1) over bar) plane. It is suggested that the loop and curved dislocations are slip ones introduced by a stress concentration during or after the growth. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2010.11.018

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Temperature-dependent carrier mobility and threshold voltage of organic field effect transistors (OFET) with tetracene single crystals pressed onto a SiO(2)/Si substrate were measured in the temperature range between 80 and 300 K. The mobility increases with decreasing temperature, reaching a maximum at 240 K. Further reduction of temperature leads to the decrease of the mobility, before leveling out below 140 K. We find that the critical temperature is strongly correlated with that of the threshold voltage which depends on the number of carriers captured in deep traps. From these temperature-dependent OFET characteristics, a carrier transport model including shallow and deep traps is suggested. (C) 2010 American Institute of Physics. [doi:10.1063/1.3499631]

DOI： 10.1063/1.3499631

Web of Science

researchmap

Language：English  

This review addresses the field of nanoscience as viewed through the lens of the scientific career of Peter Eklund, thus with a special focus on nanocarbons and nanowires. Peter brought to his research an intense focus, imagination, tenacity, breadth and ingenuity rarely seen in modern science. His goal was to capture the essential physics of natural phenomena. This attitude also guides our writing: we focus on basic principles, without sacrificing accuracy, while hoping to convey an enthusiasm for the science commensurate with Peter's. The term 'colloquial review' is intended to capture this style of presentation. The diverse phenomena of condensed matter physics involve electrons, phonons and the structures within which excitations reside. The 'nano' regime presents particularly interesting and challenging science. Finite size effects play a key role, exemplified by the discrete electronic and phonon spectra of C60 and other fullerenes. The beauty of such molecules (as well as nanotubes and graphene) is reflected by the theoretical principles that govern their behavior. As to the challenge, 'nano' requires special care in materials preparation and treatment, since the surface-to-volume ratio is so high
they also often present difficulties of acquiring an experimental signal, since the samples can be quite small. All of the atoms participate in the various phenomena, without any genuinely 'bulk' properties. Peter was a master of overcoming such challenges. The primary activity of Eklund's research was to measure and understand the vibrations of atoms in carbon materials. Raman spectroscopy was very dear to Peter. He published several papers on the theory of phonons (Eklund 1995a Carbon 33 959-72, Eklund 1995b Thin Solid Films 257 211-32, Eklund 1992 J. Phys. Chem. Solids 53 1391-413, Dresselhaus and Eklund 2000 Adv. Phys. 49 705-814) and many more papers on measuring phonons (Pimenta 1998b Phys. Rev. B 58 16016-9, Rao 1991 a Nature 338 257-9, Rao 1997b Phys. Rev. B 55 4766-73, Rao 1997c Science 275 187-91, Rao 1998 Thin Solid Films 331 141-7). His careful sample treatment and detailed Raman analysis contributed greatly to the elucidation of photochemical polymerization of solid C 60 (Rao 1993b Science 259 955-7). He developed Raman spectroscopy as a standard tool for gauging the diameter of a single-walled carbon nanotube (Bandow 1998 Phys. Rev. Lett. 80 3779-82), distinguishing metallic versus semiconducting single-walled carbon nanotubes, (Pimenta 1998a J. Mater. Res. 13 2396-404) and measuring the number of graphene layers in a peeled flake of graphite (Gupta 2006 Nano Lett. 6 2667-73). For these and other ground breaking contributions to carbon science he received the Grqffin Lecture award from the American Carbon Society in 2005, and the Japan Carbon Prize in 2008. As a material, graphite has come full circle. The 1970s renaissance in the science of graphite intercalation compounds paved the way for a later explosion in nanocarbon research by illuminating many beautiful fundamental phenomena, subsequently rediscovered in other forms of nanocarbon. In 1985, Smalley, Kroto, Curl, Heath and O'Brien discovered carbon cage molecules called fullerenes in the soot ablated from a rotating graphite target (Kroto 1985 Nature 318 162-3). At that time, Peter's research was focused mainly on the oxide-based high-temperature superconductors. He switched to fullerene research soon after the discovery that an electric arc can prepare fullerenes in bulk quantities (Haufler 1990 J. Phys. Chem. 94 8634-6). Later fullerene research spawned nanotubes, and nanotubes spawned a newly exploding research effort on single-layer graphene. Graphene has hence evolved from an oversimplified model of graphite (Wallace 1947 Phys. Rev. 71 622-34) to a new member of the nanocarbon family exhibiting extraordinary electronic properties. Eklund's career spans this 35-year Odyssey. © 2010 IOP Publishing Ltd.

DOI： 10.1088/0953-8984/22/33/334201

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Transmission electron microscopy (TEM) technique was used to investigate the structure of carbon nanowalls (CNWs). The TEM observation clearly indicated the existence of the bended graphene structure in boundary regions between the crystallites of CNWs. According to this TEM result, the first-principles calculation was employed for the bended coronene molecule as the model of the boundary region between the crystallites of CNWs, to elucidate the mechanism of the hydrogen adsorption to CNWs. The hydrogen adsorption energies onto both on-top and hollow sites become greater as the bending angle increases, because the electronic structure of the carbon atom at the adsorption site changes from sp(2) to sp(3) hybridization character by natural bond orbital analysis. Our computational result is reasonably consistent with the specific feature of hydrogen adsorption to CNWs, which had been reported in our previous work by ultraviolet photoelectron spectroscopy and temperature program desorption measurements by Kinoshita et al.[Chem. Phys. Lett. 450, 360 (2008)]. (C) 2010 American Institute of Physics. [doi:10.1063/1.3446830]

DOI： 10.1063/1.3446830

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The conductivity and magnetoresistance of graphite thin film (GTF), fabricated by plasma-enhanced chemical vapor deposition (PECVD), were investigated. Below 100 K, the conductivity was proportional to log T, and the transverse magnetoresistance (MR) was negative, whereas the longitudinal MR was small, but positive. The conductivity and magnetoresistance results are well-described by weaklocalization theory, applied to a two-dimensional disordered system. The carrier dephasing length (Lε), which was estimated from the transverse MR, varied as T-p (p = 0.05 - 0.11). This p value is an order of magnitude smaller than that of electron-electron interaction derived from Fermi liquid theory (p = 1). This small p value strongly suggests that the electronic state of GTF is different from that of typical graphite. © 2010 The Physical Society of Japan.

DOI： 10.1143/JPSJ.79.054708

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Fine structure of the Raman D band in single-wall carbon nanotubes (SWNTs) was investigated by heating and laser irradiation. It is shown that the D band is composed of three components at similar to 1313, 1340, and 1355 cm(-1), denoted by D(1), D(2), and D(3), respectively. The D(1) and D(2) intensities significantly increase with laser irradiation in air and vacuum, respectively. The D(3) intensity drastically increases with heating in air. From these results, it is suggested that the fine structure of the D band is attributed to different kinds of defects introduced in SWNTs. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.diamond.2009.12.008

Web of Science

researchmap

Language：Japanese   Publisher：The Japan Institute of Metals and Materials  

DOI： 10.2320/materia.49.320

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The growth and structure of carbon nanowalls (CNWs) on the substrate were investigated by grazing incidence X-ray diffraction. Fully-grown CNWs have a single phase of hexagonal graphite structure with relatively high degree of graphitization as the graphite powder. The preferred orientation of graphene layers is perpendicular to the substrate surface. At the initial growth state, the graphene layers are horizontally oriented. At the critical deposition time for changing the orientation, some diffraction peaks which cannot be assigned to the hexagonal graphite structure are observed. These peaks suggest the formation of a carbon allotrope which should contribute to the turning of the orientation of graphene layers. (C) 2009 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.cplett.2009.09.104

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Dislocations in large hen egg-white lysozyme (HEWL) crystals with tetragonal and orthorhombic forms were investigated by means of synchrotron monochromatic-beam X-ray topography. For the tetragonal form, not only screw dislocations but also edge ones are found to be included in predominant ones parallel to &lt; 110 &gt; directions. In addition, curved dislocations that can be related to (001)&lt; 110 &gt; slip system are observed at the crystal edges. For the orthorhombic form, predominant edge dislocations with [001] Burgers vector are stereoscopically observed. It is clarified that they are generated at or around the nucleus centre or sector boundary. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

DOI： 10.1002/pssa.200881596

Web of Science

Scopus

researchmap

Other Link： http://orcid.org/0000-0001-9105-3746

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSICAL SOC  

Transverse sound velocity of cross-linked tetragonal hen egg-white (HEW) lysozyme crystals containing large amount of water in the crystal was measured using ultrasonic pulse-echo method. All elastic constants of cross-linked crystals were observed to be C(11)=C(22)=5.50 GPa, C(12)=4.33 GPa, C(13)=C(23)=3.94 GPa, C(33)=5.22 GPa, C(44)=C(55)=0.68 GPa, and C(66)=0.84 GPa, respectively. We found that the elastic constants of the cross-linked crystals are identical to those of the intrinsic ones without cross-linking. Moreover, we found that tetragonal HEW lysozyme crystals that enclose large amount of water show decreased elastic constants (softening). In particular, the shear elastic constants C(44)=C(55) and C(66) showed more softening effect comparing with other elastic components.

DOI： 10.1103/PhysRevE.79.061917

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Lithium insertion behavior of carbon nanowall (CNW), which is a two-dimensional carbon nanostructures, was studied by cyclic voltammetry and charge/discharge measurements. It was found that CMW had reversible capacities of more than 200 mAh/g with stable charge/discharge potential like that of graphite even though the materials were produced at low temperature of 973 K. It was also found that CNW showed good responses of lithium insertion/extraction reaction because of their small and uniform particle size with well oriented graphene in nanometer scale. Heat treatment of CNW was found to purify the CNW from by-product amorphous carbon phase and the effect on their charge/discharge property was also clarified. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2009.01.012

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

Formation and structure of toughened C60 nanowhiskers (C 60NWs) were investigated. C60NWs are modified when pristine ones grown by a liquid-liquid interfacial precipitation method are kept in the growth solution for more than 3 years. The modified ones have a hexagonal solvated structure not only in the solution but also in air or a vacuum. The modified ones exhibit high strength and large elastic deformation in air, quite differing from the brittle in pristine ones in air. © 2009 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/159/1/012009

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

We show creation of paperlike thin film (Buckypaper) consisting of pseudo-two-dimensional network of boron-doped single-walled carbon nanotubes (B-SWNTs) within weakly intertube van der Waals coupling (IVDWC) state. It was formed by sufficiently dissolving as-grown ropes of B-SWNTs and densely assembling them on silicon substrate. We find that superconducting transition temperature (Tc) of 8 K under absent pressure can be induced up to 19 K by applying a small pressure to the film and that a frequency in the radial breathing phonon drastically increases with applying pressure. Discussion about IVDWC and distribution of B-SWNTs diameter imply the strong correlation. © 2009 American Institute of Physics.

DOI： 10.1063/1.3242016

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

C60-based materials such as FNWs and FNTs are new candidates for organic electronics and solar cells. Recently, a method to produce vertically-aligned fullerene microtube crystals (VFMTs) has been established. The VFMTs are exepected to be used as field emission devices, solar cells, fuel cells, and so forth. To realize such attractive applications, structures and arrangements of VFMTs should be controlled. In oder to know the growth mechanism of VFMTs, Scanning electron microscopy (SEM) observations were performed for several injection periods of VFMTs. In the initial stage of synthesis (IPA injection time of 60 min), vertically aligned thin non-tubular fullerene microwhiskers (VFMWs) formed on AAO substrates. The outer and inner diameter of VFMWs became increased with increasing the injected amount of IPA. And also the size of tube holes became larger. The tubular structures appeared at an injection time of around 90 min. At an injection time of 120 min, vertically aligned FMTs with hexagonal cross sections and holes were obtained and their diameter and structure did not change up to the final stage of injection time of 3 00 min. © 2009 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/159/1/012012

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

The solvent molecules contained in C60NWs affect not only the shape but also the crystal structure of C60NWs. The solvents contained in C60NWs were found to be toluene and IPA by the GC-MS analysis. The most abundant solvent was toluene and the quantity of residual toluene in the as-prepared C60NWs was about 7 mass%. The quantity of impurity solvents is reported for the as-prepared, air-dried, vacuum-dried and heat-treated C60NWs. © 2009 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/159/1/012010

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Single-walled carbon nanotubes (SWNTs) irradiated with laser were investigated by Raman spectroscopy. The intensity of D band related to defects increased with the laser irradiation. It should be noticed that the corresponding change was observed for G-peak associated with metallic SWNTs that is related to the electron-phonon coupling with Kohn anomaly. The upshift and narrowing of the G-peak occur due to the laser irradiation. The G-peak can recover the original one due to the thermal annealing. On the other hand, G band associated with semiconducting SWNTs remained unchanged even after the laser irradiation. This means that the laser-induced defects significantly affect phonons in metallic SWNTs, compared with Semiconducting ones, and can control the electron-phonon coupling. (C) 2008 American Institute of Physics.

DOI： 10.1063/1.2990659

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC APPLIED PHYSICS  

The characteristics of 5-7 pair couple defects formed in single-walled carbon nanotubes were investigated. For armchair nanotubes with diameters from 6.8 to 13.6 angstrom, such defects were formed by removing atoms. Structural optimization, which was carried out using tight-binding molecular dynamics, resulted in the bending deformation of the nanotubes due to the defects. The resulting stable structure was found to change with the number of atoms removed, showing a bending angle of 16.6 degrees for a diameter of 10.7 angstrom. The dependence of bending angle on the diameter of nanotubes was analysed using a simple model. As results, several sets of 5-7 pair couple defects were found to be necessary in order to induce plastic deformation that was experimentally observed in nanotubes.

DOI： 10.1143/JJAP.47.6601

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

DNA-wrapped single-wall carbon nanotubes (DNA-SWNT hybrids) prepared from different diameter HiPco- and Arc-SWNTs were investigated by atomic force microscopy. The mean diameter of DNA-HiPco-SWNT hybrids is 1.94 nm that is consistent with one HiPco-SWNT (similar to 0.9 nm) wrapped by DNA (similar to 1 mn). On the other hand, the mean diameter of DNA-Arc-SWNT hybrids is 3.74 nm that can correspond to one Arc-SWNT (similar to 1.4 nm) wrapped by several layers of DNA. It is suggested that the DNA-wrapping mechanism for large diameter Arc-SWNTs is different from that for small diameter HiPco-SWNTs. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.diamond.2008.01.010

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

We investigated dislocation motions in C-60 crystals after indentation, by x-ray topography and etching method. A rosette pattern was observed around an indentation after etching. The dislocations in the rosette were moved by thermal annealing and the positions in the dislocations were measured before and after annealing by the double etching method. The annealing temperature dependence of dislocation motions was measured in the temperature range 490-610 K. The characteristics of dislocation motion showed dislocation locking due to impurity atmosphere. It was concluded that oxygen and oxide of C60 molecules could lock the dislocations. Moreover, a pair of pits in the rosette pattern were observed after annealing. It corresponded to a pair of Shockley's partial dislocations.

DOI： 10.1088/0022-3727/41/7/074002

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Mechanical properties of high quality tetragonal hen egg-white lysozyme single crystals which are one type of protein crystal were investigated by the indentation method. The indentation marks were clearly observed on the crystal surface and no elastic recovery of them occurred. The value of the micro-Vickers hardness in the wet condition was estimated to be about 20MPa at room temperature. The hardness greatly depended on the amount of intracrystalline water (mobile water) contained in the crystals. The hardness increased with increasing evaporation time to air at room temperature. It reached the maximum at about 260MPa, which is 13 times as much as that in the wet condition. The origin of such a change in hardness was explained in terms of the dislocation mechanisms in lysozyme single crystals.

DOI： 10.1088/0022-3727/41/7/074019

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Electronic structure of carbon nanowalls (CNW) was measured by ultraviolet photoelectron spectroscopy (UPS) in comparison with highly oriented pyrolitic graphite (HOPG). While the interlayer band of CNWs was observed at same energy of that in HOPG, the a and pi bands were observed as are in carbon nanotubes. Electronic effects by deuterium adsorption were investigated by combination of UPS and temperature programmed desorption (TPD) measurements. Deuterium adsorption preferably occurred in the boundary regions between crystallites in CNWs and enhanced the density of states associated with them. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2007.11.038

Web of Science

researchmap

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The structural change of C60 nanotubes (C60NTs) by heating in vacuum was investigated using thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM) and Raman spectroscopy. The C 60NTs were prepared by use of a pyridine solution saturated with C60 and isopropyl alcohol (IPA). A weight loss of about 4 % in the C60NTs dried at room temperature was observed by heating up to 400 °C in a N2 atmosphere, and the C60NTs started to decompose from about 600 °C. The Ag(2) peak of as-prepared C 60NTs shows a Raman shift indicating one-dimensionally polymerized C60, while the C60NTs heated at 100 °C ∼ 500 °C in vacuum show Ag(2) peaks characteristic of van der Waals C60 crystals, suggesting a change of bonding state of C60 molecules by heat treatment. TEM observations show that the crystallinity and surface morphology of C60NTs are degraded by high-temperature heat treatment in vacuum. © 2008 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejsmas.128.317

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The mechanical properties of C60 nanowhiskers (C 60NWs) grown in a solution by a liquid-liquid interfatical precipitation method were investigated by a bending method. C60NWs in the solution exhibited large elastic deformation where they recovered for large bending with a curvature of 290 μm. On the other hand, C60NWs in air were broken even for small bending with only a 650 urn curvature. From the analysis of the bending, the yield stress or breaking stress for C 60NWs in air is estimated to be 7.7 MPa, that is larger by one order compared with 0.7 MPa for bulk C60 crystals. In addition, it is shown that the Young's modulus for C60NWs in the solution is 8.9 GPa, that is below a half of 20 GPa for bulk C60 crystals. © 2008 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejsmas.128.321

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We clearly observed the dislocation of protein crystals by means of synchrotron white-beam topography. According to the invisibility criterion (g . b = 0) of dislocation images, it was found that the predominant dislocations are of screw character with Burgers vector b = (110). These results are discussed in terms of elastic energy of dislocations. (C) 2007 Published by Elsevier B.V.

DOI： 10.1016/j.physb.2007.09.053

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Simulations of double-walled carbon nanotubes under bending deformation using the tight-binding molecular dynamics method were carried out. Five- and seven-membered ring pair defects were formed after emission of several atoms from the tube structure. These defect pair couples have different structures corresponding to the number of emitted atoms and stabilize the resulting nanotubes. Our results imply that the defect pair couples represent one of the potential origins of the experimentally observed plastic deformations that have been shown to occur in double-walled carbon nanotubes. The various defects obtained by the simulations are discussed in relation to other defect types. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2821247

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Crystal defects, especially dislocations, in hen egg-white lysozyme crystals that have multiple polymorphisms, for example, tetragonal, orthorhombic, monoclinic forms, etc., were investigated by means of synchrotron monochromatic-beam X-ray topography. The observed topographic images of dislocations were much clearer compared to those of any protein crystals that have been reported so far. It was demonstrated that millimeter-size crystals larger than extinction lengths for X-ray topographic reflections are required to obtain clear images, that is, direct images, for protein crystals. In addition, the weak-beam technique was found to be useful for obtaining clearer images. Straight, curved, and loop-type dislocations were clearly resolved on the topographs. This shows that dislocations observed in common inorganic crystals and organic crystals of small molecules can also be introduced even into protein crystals. The shape and configuration of dislocations strongly depended on the crystal form. This suggests that the growth mechanisms in the different crystal forms studied may differ. X-ray topography provides a useful tool for the characterization of protein crystal dislocations.

DOI： 10.1021/cg7009447

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Orthorhombic hen egg-white (HEW) lysozyme crystals were examined by means of synchrotron X-ray topography by the white beam technique. Four kinds of straight dislocations were clearly observed. From the extinction criterion of the dislocation images, Burgers vectors were identified to be [001], [1̄10] and [01̄1]. © 2007 WILEY-VCH Verlag GmbH &amp
Co. KGaA.

DOI： 10.1002/pssa.200675679

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：MATERIALS RESEARCH SOCIETY JAPAN-MRS-J  

The wall of as-prepared C-60 nanotubes contains solvent molecules and the wall structure changes by drying. This change of wall structure was examined by Raman spectrometry. The structural change of C-60 nanotubes by heating was also investigated using the Raman and TEM analyses. The C-60 nanotubes heated at 300 degrees C in vacuum turned to a disordered structure with amorphous carbon, and finely dispersed copper nanocrystals were observed by HRTEM, suggesting that copper worked as a catalyst to decompose the C-60 nanotubes.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

G band Raman spectra for DNA-wrapped single-wall carbon nanotubes (SWNTs) in aqueous solution and air have been investigated. The lower-frequency mode in the G band associated with semiconducting SWNTs is drastically suppressed by DNA-wrapping. In addition, the broad and asymmetric feature of the Breit-Wiger-Fano (BWF) line in the G band associated with metallic SWNTs is vanished by DNA-wrapping in aqueous solution. The BWF feature strongly appears again after the DNA-wrapped SWNTs are dried in air. These changes in the G band are discussed in the light of the vibrations and electronic properties in the SWNTs wrapped by DNA. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2006.10.019

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

DNA-wrapped single-wall carbon nanotubes (DNA-SWNT hybrids) under various humidity conditions were investigated by Raman spectroscopy. The G band, especially Breit-Wigner-Fano (BWF) line, in the Raman spectra of DNA-SWNT hybrids strongly depends on the relative humidity. In the high humidity range above 55%, the BWF coupling increases with decreasing humidity. On the contrary, in the low humidity range below 55%, the BWF coupling decreases with decreasing humidity. The origin of such humidity dependence is discussed in the light of the behavior of the absorption of the water vapor on DNA in air. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2006.09.048

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST PURE APPLIED PHYSICS  

We show that diesel soot can be recycled as a carbon source for the synthesis of single-wall carbon nanotubes (SWNTs). The synthesis of SWNTs was carried out by the laser vaporization of diesel soot. The presence of SWNTs was confirmed by Raman spectroscopy and transmission electron microscopy. SWNTs produced in this way should provide economic benefits and also contribute to a cleaner environment.

DOI： 10.1143/JJAP.45.8027

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Raman spectra of carbon nanowalls (CNWs) grown using dc plasma-enhanced chemical vapor deposition were analyzed. The Raman spectra of CNWs exhibited G and D bands at similar to 1580 and similar to 1350 cm(-1) respectively. It is found that the bandwidth of the G band is relatively narrow, even when the peak intensity ratio of D band to G band is significantly high. This spectral feature of CNWs is distinguished from those of typical graphitelike carbons reported so far. From the comparison of these spectral features, it is shown that CNWs are composed of small crystallites with a high degree of graphitization. (c) 2005 American Institute of Physics.

DOI： 10.1063/1.1900297

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Photo-assisted growth of C-60 nanowhiskerS (C(60)NWs) by the liquid-liquid interfacial precipitation method was demonstrated with various wavelengths of ultraviolet-visible light. It is found that the growth rate of C(60)NWs strongly depends oil the wavelength of the illumunation light. The growth rate of C(60)NWs is significantly promoted by the light illumination with only wavelengths between 600 and 625 nm. The number of long C(60)NWs reaches a maximum at 600 nm. The origin of photo-assisted C60NW growth is discussed in the light of the mechanism of optical absorption in C-60 solution. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2004.10.020

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

Two-dimensional carbon nanostructures called carbon nanowalls (CNWs) were fabricated using dc plasma-enhanced chemical vapor deposition with a gas mixture of CH4, H2 and Ar. CNWs were vertically grown on quartz and Si substrates at temperatures of 500 to 800°C. The size of CNWs was controlled by growth conditions such as CH4/H2 ratio and substrate temperature. The structures of CNWs were characterized by Raman spectroscopy. The spectral features of CNWs are distinguished from those of typical graphite-like carbons reported so far. From the comparison of the spectral features, it is shown that CNWs are composed of small crystallites with a high degree of graphitization. ©2005 IEEE.

DOI： 10.1109/NANO.2005.1500805

Scopus

researchmap

DOI： 10.1107/S0108767305085910

Web of Science

researchmap

DOI： 10.1107/S0108767305081183

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The G band in Raman spectra of single-wall carbon nanotube (SWNT) bundles is studied between 3 and 500 K. The G band is best fit with five Lorentzian lines and one Breit-Wigner-Fano (BWF) line, indicating coupling of phonons to the electronic continuum of metallic SWNTs. It is found that the line width of the BWF line decreases with increasing temperature. This temperature-dependent behaviour is contrary to that of the Lorentzian lines, where the line width increases with increasing temperature. The coupling constant [1/q] of the BWF line is also found to decrease with increasing temperature. These temperature-dependent behaviours of BWF line provide evidence that it is the bundling effect of SWNTs that greatly enhances the BWF coupling. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2004.11.001

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSICAL SOC  

Longitudinal sound velocity of tetragonal hen-egg-white (HEW) lysozyme crystals was measured during air drying by ultrasonic pulseecho method. The sound velocity increases with exposure to open air and approaches a constant value. The maximum value is similar to2900 m/s that is about 1.6 times as much as that of original one before drying. In addition, the sound velocity clearly recovers to original one after immersing the dried crystal in solution. Therefore, the sound velocity in tetragonal HEW lysozyme crystals can be reversibly changed due to dehydration and rehydration. These changes in sound velocity are discussed in the light of water-mediated intramolecular and intermolecular interactions in the crystals.

DOI： 10.1103/PhysRevE.69.051921

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

The pattern change in a laminar flow of molten polycarbonate in a disk mold was experimentally investigated by altering the flow velocity. By use of a light-scattering method, a radial pattern characterized by a periodic array of needlelike regions and the matrix was found to form as the flow velocity was increased. The density distribution of the polycarbonate molecules was an essential factor for pattern formation. As a result of the formation of this pattern, it was found that the boundaries between the needlelike regions and the matrix emitted weak fluorescence in the wavelength range of 600-700 nm under laser irradiation. An analysis indicated that transitions between excited pi electron states in the phenylene groups were the sources of this fluorescence and that a key factor behind its occurrence was a decrease in the molecule density at the boundaries. These results reveal that the radial-pattern formation changes the fluorescence property of polycarbonate in the visible and near-infrared regions. (C) 2004 Wiley Periodicals, Inc. J AppI Polym Sci 92: 468 - 473, 2004.

DOI： 10.1002/app.20016

Web of Science

researchmap

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL MUNKSGAARD  

Large tetragonal hen egg-white ( HEW) lysozyme crystals have been grown by a salt concentration-gradient method. The grown crystals, of thicknesses greater than 1.5 mm, were observed by means of X-ray topography using white-beam synchrotron radiation. Line contrasts clearly appeared on the Laue topographs. Extinction of the line images was observed in specific reflections. These results mean that the observed lines correspond to dislocation images. From the extinction criterion it is shown that the predominant dislocations are of screw character with [110] Burgers vectors. In addition, dislocation loops with [001] Burgers vectors have been found in a tetragonal HEW lysozyme crystal including some cracks. These results are discussed in the light of dislocation elastic energy and slip systems in the crystals.

DOI： 10.1107/S0909049503020417

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

C-60 nanowhiskers are grown by a liquid-liquid interfacial precipitation method at 21 degreesC. It is found that the growth of the nanowhiskers is promoted under illumination even with weak room light (fluorescent light). The maximum of their lengths exceeds 1 mm where the diameter is about 250 nm. From Raman scattering measurements, it is shown that C-60 molecules in the pristine nanowhiskers are bonded by weak van der Waals forces. The nanowhiskers is easily polymerized under irradiation with laser light. The cross section for this photo-polymerization is much large compared with that for intrinsic C-60 bulk crystals. (C) 2003 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0009-2614(03)00723-1

Web of Science

researchmap

Language：English   Publisher：ELSEVIER SCIENCE BV  

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

A radial pattern is found to form in the polycarbonate (PC) substratum of a recordable compact disk. Characteristic features of the pattern axe that it is composed of about 80 needle-like regions, the shape of which closely resembles a thin film. In addition, white light is found to scatter at the needle-like region/matrix boundaries. This suggests that the PC substratum may have inferior transparency due to the formation of this pattern. Thus, it is important to understand the bifurcation of the radial-pattern formation from the viewpoint of materials science and engineering. Based on the mechanics of the PC viscous fluid, it has been found that the bifurcation of the pattern formation has a Reynolds number of about 10(-3). (C) 2001 American Institute of Physics.

DOI： 10.1063/1.1400778

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The microhardness of C70 crystals was investigated in the temperature range of 295-425 K. The hardness gradually decreased with increasing temperature. The photoinduced hardening was observed after the long-time illumination of light. The hardening reached the maximum near the phase transition temperature of 348 K. These results are discussed and compared with those of C60 crystals. © 2001 American Institute of Physics.

DOI： 10.1063/1.1375804

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

C-60 crystals were deformed at 295 K. The stress-strain curves show a behaviour similar to that typical of fee metals. The yield stress is about 0.7 MPa. Slip lines were observed by optical microscopy and atomic force microscopy. Their maximum step height is about 1600 nm at 24% strain. It is suggested that the dislocation multiplication in C-60 crystals is mainly controlled by a Frank-Read source mechanism.

DOI： 10.1080/01486101300060937

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We have succeeded in the first measurement of the sound velocity of lysozyme single crystals using an ultrasonic pulse-echo method. The sound velocity along the [110] crystallographic direction in the tetragonal crystals is obtained to be 1817 m/s in the solution with pH 4.3 at 20 degreesC. The corresponding elastic constant C-11 + C-66 is evaluated to be approximately 3.99 GPa. Assuming the isotropic body, the dynamic Young modulus is estimated to be 2.70 GPa. The temperature and pH dependences of the sound velocity are also observed. Their mechanisms are discussed in relation to the inter-molecular contacts in the crystal. (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0009-2614(00)01267-7

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Laue topography of the tetragonal crystals of hen egg-white lysozyme has been carried out using synchrotron radiation. Straight-line images extending from the core part to the growth fronts were observed and interpreted as dislocations. They had the displacement vectors parallel to the line; they are similar type of dislocations common to the crystals grown from solutions. The Laue spots showed uniform distortion. The water filter 10 mm thick was effective in avoiding radiation damages. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-0248(99)00344-9

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We demonstrate that single-wall carbon nanotubes (SWNT) can be produced by an are-discharge method using a catalyzed coal carbon source. Characterization by resonant Raman scattering and electron microscopy confirm that this material contains SWNT with properties similar to graphite-derived SWNT. 'Web-like' material from our growth process has an estimated yield of 45 wt.% of carbon as SWNT, while the average chamber yield is approximately 20 wt.% C, as determined by FT-Raman and HRSEM measurements. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0009-2614(99)00725-3

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Dislocation-free crystals of 2,3-dimethylnaphthalene were grown from a melt by the Bridgman method. The characteristics and motion of dislocations in the crystals were investigated by X-ray topography. The dislocations developed and expanded from highly strained regions in the crystals when they were annealed at higher temperature (102 degrees C)just below the melting point (107 degrees C). In the case of annealing at 60 and 80 degrees C, no motion of dislocations was observed. The Burgers vectors of the moving dislocations were identified to be parallel to the [1 1 0] and [0 1 0] direction. The [1 1 0] (0 0 1) and [0 1 0] (0 0 1) system, therefore was suggested as one of the slip systems. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-0248(98)01097-5

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Vickers microhardness of protein crystals of hen egg-white lysozyme was investigated by the indentation method. The indentations were clearly made on the crystal surface and no large elastic recovery of them was observed. The value of the hardness was estimated to be 0.2 kgf/mm(2) on the crystals just after they were transferred from solution to air. The hardness drastically increased with increasing exposure time to air at room temperature. The maximum hardness was 20 kgf/mm(2), which is almost the same as those of van der Waals crystals. The origin of such a change in hardness is explained in terms of the water contained in protein crystals. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-0248(98)01096-3

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The photoinduced indentation hardening of C-60 crystals was investigated in ultraviolet-visible light. The hardening strongly depended on the wavelength of the illumination light: the magnitude increased with increasing wavelength, and then reached a maximum at 700 nm. This indicated that red light is more effective than ultraviolet light in the hardening. The wavelength dependence of the hardening is discussed in terms of an interplay between the effective depth of the photoinduced polymerization and the penetration depth of the indenter. (C) 1998 American Institute of Physics. [S0021-8979(98)09316-5].

DOI： 10.1063/1.368324

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The effect of light on the hardness of C-60 crystals was investigated. The hardness increased after the crystals were illuminated with white light. Such a photo-illumination hardening was effective in a temperature range of 298-380 K. The photopolymerized C-60 molecules near the crystal surface were responsible for the hardening. The anomalous temperature dependence of the hardness at temperatures higher than 300 K, which we previously have observed, is explained as due to the photo-illumination hardening. (C) 1997 American Institute of Physics. [S0021-8979(97)08921-4].

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MATERIALS RESEARCH SOCIETY  

The growth of the shells of C-60 crystals was carried out under various conditions. The detailed structures of the grown shells were investigated by transmission electron microscopy and Raman spectroscopy. The shells were formed during thermal sublimation of the C-60 crystals, which were irradiated with white light in air, The shells were mainly composed of a kind of amorphous carbon. From these results, it is suggested that the oxygen-induced disintegration of C-60 cages is responsible for the shell formation.

DOI： 10.1557/JMR.1997.0211

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

N-methylurea crystals were grown from the melt by Czochralski method and their perfections were assessed by X-ray topography. The individual defects in the grown crystals were observed on the topographs, since the density of defects was low. The crystal defects, especially grown-in dislocations, are characterized.

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPIE-INT SOC OPTICAL ENGINEERING  

Photoluminescence spectra of C-60 crystals with high quality was measured before and after the mechanical deformation. New peak at 685 nm appeared after the deformation. The peak was observed only at temperatures lower than about 90 K, where its intensity decreases with increasing temperature. The temperature dependence of the peak intensity was correlated with that of main other peak at 735 nm, which would originates in intrinsic C-60 crystals. From these results, the origin of the peak at 685 nm is discussed in the light of crystal defects, especially dislocations.

DOI： 10.1117/12.279250

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPIE-INT SOC OPTICAL ENGINEERING  

The effect of light on the hardness of C-60 crystals was investigated. The hardness increased with the development of illumination time, and then reached a constant value. The hardening phenomenon was clearly observed at temperatures lower than about 390 K. In addition, it was shown that the red light with the wavelength of about 700 nm leads to the maximum effect for the hardening. The origin of the hardening is discussed in the Light of the photo-induced polymerization of C-60 molecules in the crystals.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

C-60 single crystals were grown from the vapor by a continuous-pulling technique. Large C-60 crystals up to a size of 4.5 x 3.0 x 1.5 mm(3) were obtained. The structural perfection of the as-grown crystals was examined by X-ray topography and etching. The ''grown-in'' dislocation density was estimated to be of the order of 10(4) cm(-2). Slip systems, which are introduced in C-60 crystals by microindentation, were investigated using an etching method.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN J APPLIED PHYSICS  

Defects in anthracene were investigated by the positron annihilation technique. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured in the temperature range between 305 K and 516 K. The lifetime of positrons annihilated from the delocalized state was determined to be 0.306 ns around room temperature. Below the melting point, the observed temperature dependence of the line shape parameter S was explained assuming the formation energy of thermal equilibrium defects was 1 eV. Above the melting point, the pick-off annihilation of ortho-positronium in open spaces was observed, where the size of these spaces was estimated to be 0.2 nm(3). The annihilation of positrons from the self-trapped state was also discussed.

Web of Science

researchmap

Language：English   Publisher：INT UNION CRYSTALLOGRAPHY  

DOI： 10.1107/S0108767396078865

Web of Science

researchmap

Language：English   Publisher：INT UNION CRYSTALLOGRAPHY  

DOI： 10.1107/S0108767396079159

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

A behavior of plastic deformations of C-60 single crystals was examined using the microindentation technique. Not only slip lines but also dislocation etch pits were observed around the indentation on the crystal surface. It is confirmed that the slip systems in C-60 single crystals are {111}[110] in a temperature range of 240 K to 450 K. This means that, even in a simple cubic phase below a phase transition temperature of similar to 260 K, the slip systems an the same as a face-centered-cubic phase. (C) 1995 American Institute of Physics.

DOI： 10.1063/1.114314

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier Science B.V.  

Photoluminescence spectra of mechanically damaged C60 single crystals were investigated. Two main spectral peaks were observed at 685 and 735 nm, which originate from structural defects, such as dislocations, introduced near the crystal surface and in a perfect region of the crystal, respectively.

DOI： 10.1016/0022-2313(95)00147-6

Scopus

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE PUBL B V  

Web of Science

researchmap

DOI： 10.1016/0022-0248(95)00491-2

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Systematic studies of crystal growth of benzophenone by the Czochralski method and characterizations of dislocations in the grown crystals were performed. The dislocations introduced during the crystal growth were observed using X-ray topography. The characteristics of these dislocations were determined by an invisibility condition of dislocation images. Furthermore they were analyzed by a minimum energy criterion of preferred directions of dislocation lines. From these characterizations, a shorter Burgers vector c [001] was found to be generated in crystals grown along directions of [001], [010] and [100]. Several longer Burgers vectors were also found to exist in spite of their higher dislocation energies. These characteristics of grown-in dislocations are discussed in relation to corresponding dislocation energy. © 1994 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.33.1995

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The mechanical properties of C60 crystals were investigated using the Vickers microhardness indentation technique. Firstly, the temperature dependence of the hardness was measured at temperatures from about 240 to 470 K. A discontinuous change in the hardness was observed at around 260 K. Such a marked change in hardness is due to the phase transition of the C60 crystal. At temperatures higher than 300 K, the hardness showed an anomalous behavior: the hardness increased with increasing temperature and reached a maximum at around 370 K. © 1994 The American Physical Society.

DOI： 10.1103/PhysRevB.49.14945

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Urea single crystals were grown by solution growth and melt growth by the Czochralski method. The perfection of the grown crystals was evaluated by x-ray topography. The crystal defects, especially dislocations, in the crystals were characterized by analysis of their images. As a result, the Burgers vectors of the dislocations in urea crystals were determined to be [001]. Almost every long straight dislocation in the crystals was a type of screw dislocation.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Benzophenone single crystals were grown by the Czochralski method. The dislocations introduced during the crystal growth were examined using X-ray topography. Double images of single dislocations were found on the topographs taken in some reflection planes. The Burgers vector of predominant grown-in dislocations was estimated from analysis of the dislocation images on the basis of kinematical theory. © 1992 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.31.2202

Scopus

researchmap

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

&lt;p&gt;我々は、これまでタンパク質結晶の塑性といった力学的性質の先導的な研究を行い、その塑性変形のメカニズムが転位の運動によるものであることを報告してきた。タンパク質結晶のひとつであるグルコースイソメラーゼ結晶は擬BCC構造をもつ。今回、グルコースイソメラーゼ結晶に導入された転位のX線トポグラフィ観察とキャラクタリゼーションに初めて成功した。発表ではBCC金属との比較と、タンパク質結晶のすべり変形の一般性について議論する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_2739

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.72.2.0_2268

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.71.1.0_2765

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.70.2.0_2441

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Authorship：Lead author,　Corresponding author   Publisher：Jenny Stanford Publishing  

DOI： 10.1201/b15656

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

J-GLOBAL

researchmap

Language：Japanese  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：High Energy Accelerator Research Organization (KEK)  

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

CiNii Books

researchmap

Language：Japanese   Publisher：オ-ム社  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：English  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

J-GLOBAL

researchmap

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.63.2.4.0_784_1

researchmap

Language：Japanese   Publisher：The Physical Society of Japan  

DOI： 10.11316/jpsgaiyo.63.1.4.0_799_2

researchmap

Language：Japanese  

CiNii Books

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：English   Publisher：WILEY-V C H VERLAG GMBH  

Orthorhombic hen egg-white (HEW) lysozyme crystals were examined by means of synchrotron X-ray topography by the white beam technique. Four kinds of straight dislocations were clearly observed. From the extinction criterion of the dislocation images, Burgers vectors were identified to be [001], [110] and [011]. (c) 2007 WILEY-VCH Vertag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/pssa.200675679

Web of Science

researchmap

Language：English   Publisher：AMER INST PHYSICS  

The nanostructure of carbon nanowalls (CNWs), composed of a stack of several graphite sheets, was investigated by transmission electron microscopy. Our detailed analysis revealed that numerous graphite regions with an average size of about 20 nm were formed in the CNWs. The formation of these regions originates from the introduction of lattice defects such as dislocations and the slight rotation of the graphite sheets. On this basis, it is concluded that the graphite regions, so-called "nanographite domains," are the constitutional units of the CNWs. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2728781

Web of Science

researchmap

Language：English   Publisher：AMER INST PHYSICS  

The nanostructure of carbon nanowalls (CNWs), composed of a stack of several graphite sheets, was investigated by transmission electron microscopy. Our detailed analysis revealed that numerous graphite regions with an average size of about 20 nm were formed in the CNWs. The formation of these regions originates from the introduction of lattice defects such as dislocations and the slight rotation of the graphite sheets. On this basis, it is concluded that the graphite regions, so-called "nanographite domains," are the constitutional units of the CNWs. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2728781

Web of Science

researchmap

Language：English   Publisher：AMER INST PHYSICS  

The defects in single-wall carbon nanotubes irradiated with a 248 nm pulsed excimer laser were studied using Raman spectroscopy. The thermal relaxation kinetics of the laser-induced defects was examined at sample temperatures from 296 to 698 K. Two relaxation processes are revealed; one is the fast process with an activation energy of 0.4 eV and the other is the slow process with an activation energy of 0.7 eV. These two processes can correspond to vacancy-interstitial recombination and vacancy migration along the tube axis, respectively.

DOI： 10.1063/1.2721751

Web of Science

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：English  

The defects in single-wall carbon nanotubes irradiated with a 248 nm pulsed excimer laser were studied using Raman spectroscopy. The thermal relaxation kinetics of the laser-induced defects was examined at sample temperatures from 296 to 698 K. Two relaxation processes are revealed
one is the fast process with an activation energy of 0.4 eV and the other is the slow process with an activation energy of 0.7 eV. These two processes can correspond to vacancy-interstitial recombination and vacancy migration along the tube axis, respectively. © 2007 American Institute of Physics.

DOI： 10.1063/1.2721751

Scopus

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：English   Publisher：JAPAN SOC APPLIED PHYSICS  

Tetracene single-crystal field-effect transistors (FETs) were fabricated using fresh cleaved tetracene single crystals. In order to obtain a fine contact between the tetracene crystals and the substrate, a stress was applied using an Instron-type machine. Carrier mobility was measured as a function of applied stress and it was observed that 0.5 cm(2)/(VS) was the highest mobility under the optimum applied stress.

DOI： 10.1143/JJAP.45.5238

Web of Science

researchmap

We report the characterization of electrical properties for multi-walled carbon nanotubes (MWNTs) synthesized by the arc-discharge method, as to the difference of characteristics between two diameters of 10 nm and 100 nm. In a result of Raman spectrums, we have observed clear radial-breathing-mode peak at approximately 255 cm-1, which corresponds in turn to an innermost diameter of ∼2 nm in the MWNT, and shows a good agreement with the TEM image of diameter of the thin MWNT. The results of two- and fourterminal measurements of the thin MWNTs show a power-law behavior as expected for the Tomonaga-Luttinger liquid model. The power-law exponent, α ∼ 0.4, seems consistent with the one-dimensional nature of the transport in these structures. We have also investigated the thick MWNTs. © 2006 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/38/1/009

Scopus

researchmap

Language：English   Publisher：AMER INST PHYSICS  

Breit-Wigner-Fano (BWF) Raman line in DNA-wrapped single-wall carbon nanotubes (SWNTs) was investigated. For as-produced HiPco SWNT bundles, the asymmetric profile of BWF line is clearly observed with an excitation energy of 2.33 eV. The asymmetric feature almost disappears in isolated HiPco SWNTs by DNA wrapping in aqueous solution. Such a significant change provides evidence that the asymmetric feature of BWF line is attributed to the bundling effect of SWNTs. In addition, the asymmetric feature of BWF line strongly appears even when the DNA-wrapped SWNTs are exposed to air. This means that the rebundling in the DNA-wrapped SWNTs can occur due to drying. (C) 2006 American Institute of Physics.

DOI： 10.1063/1.2196249

Web of Science

researchmap

Language：English   Publisher：ELSEVIER SCIENCE BV  

The rocking curve widths of tetragonal lysozyme crystals were treasured. Typical full-width half-maximum (FWHM) of the rocking curve of crystals grown from a pure lysozyme solution were 0.004-0.006 degrees, while those crystals containing 5% lysozyrne dieter were 0.006-0.010 degrees. X-ray topography experiments revealed that dislocations existed in crystals containing the lysozyme dieter. These dislocations are one of the causes of rocking curve width broadening. 2 x 10(4) cm(-2) pits were observed on the {1 0 1} face in contaminated crystals, but few, if any pits were observed in either face of the pure crystals. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2005.12.094

Web of Science

researchmap

Language：English   Publisher：AMERICAN PHYSICAL SOC  

Success in measuring transverse sound velocity allowed us to determine, for the first time, all six elastic constants of a protein crystal. An ultrasonic pulse-echo method was used to perform sound velocity measurements on tetragonal hen egg-white (HEW) lysozyme crystals that were partially dehydrated at 42% relative humidity. The measurements were performed using the (110), (101), and (001) crystallographic faces. Thus, all six elastic constants of the dehydrated tetragonal HEW lysozyme crystals were determined: C-11=C-22=12.44 GPa, C-12=7.03 GPa, C-13=C-23=8.36 GPa, C-33=12.79 GPa, C-44=C-55=2.97 GPa, and C-66=2.63 GPa. In addition, for the hydrated crystals, the longitudinal sound velocities along the [110] direction and the direction normal to the (101) face were measured. From these results, all the components of elastic constants in the hydrated crystals were extrapolated.

DOI： 10.1103/PhysRevE.73.041910

Web of Science

researchmap

Language：English   Publisher：ELSEVIER SCIENCE BV  

It is well-known that the carrier mobility of an organic field effect semiconductor (FET) depended on the crystal quality and/or the crystal perfection of the organic thin films [T.W. Kelly, D.V. Muyres, P.F. Baude, T.P. Smith, T.D. Jones, Mater. Res. Soc. Symp. Proc. 771 (2003) L6.5.1; D.J. Gundlach, J.A. Nichols, L. Zhou, T.N. Jackson, Appl. Phys. Lett. 80 (2002) 2925; H.K. Lauk, M. Halik, U. Zschieschang, G. Schmid, W. Radlik, J. Appl. Phys. 92 (2002) 5259; M. Shtein, J. Mapel, J.B. Benziger, S.R. Forrest, Appl. Phys. Lett. 81 (2002) 268; D. Knipp, R.A. Street, A.R. Volkel, Appl. Phys. Lett. 82 (2003) 3907; R. Ruiz, A.C. Mayer, G.G. Malliaras, Appl. Phys. Lett. 85 (2004) 4926; R.W.I. de Boer, M.E. Gershenson, A.F. Morpurgo, V. Podzorov, Phys. Stat. Sol. A 201 (2004) 1031]. To improve the crystal quality of the thin film many efforts were made. One of the important improvements was the surface treatment of the substrate. The tetracene thin film FET (top contact structure) was fabricated using the substrate, which was coated by a spin-coating method with a 0.1% poly alpha-methylstyrene (AMS) solution. The crystal quality was improved by this treatment so that the carrier mobility was higher than that of non-treatment. The maximum mobility of the AMS-treated sample was obtained to be 0.12 cm(2)/V S. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2005.12.071

Web of Science

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：English  

J-GLOBAL

researchmap

Language：English   Publisher：The Mass Spectrometry Society of Japan  

Intact soot exhausted from diesel engines from a large cargo ship and from a farm tractor, which work with heavy and light oil respectively, has been analyzed using laser desorption/ionization (LDI) mass spectrometry. Caged carbon clusters (or fullerene family) were detected as molecular ions M^+· with relatively intense peaks at <i>m/z</i> 600, 720, and 840 corresponding to C₅₀, C₆₀, and C₇₀, respectively. There were also other even number carbon clusters C_2<i>n</i> (<i>n</i>=20-142 or higher). Small carbon clusters C_<i>n</i> (<i>n</i>=7-29) with the magic number <i>n</i>=7, 11, 15, 19, 23, and 27 were also observed in the LDI mass spectra. The LDI mass spectra of a fullerene C₆₀ (99%) and intact soot showed definite metastable ion peaks originating from successive C₂ loss from molecular ions. It was confirmed that under the same LDI conditions the laser vaporization of graphite never gives any products of the fullerene family or even number carbon clusters.

DOI： 10.5702/massspec.54.39

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/00276531215?from=CiNii

Language：Japanese   Publisher：日本結晶成長学会  

The characteristics of crystal perfection in monoclinic hen egg-white (HEW) lysozyme crystals were observed by synchrotron x-ray topography and locking curve. As a result, the clear dislocation images were obtained by the topography. The locking curves from various diffraction planes showed anisotropic behaviors on the half-width. We will discuss the relationship between the dislocations and the half-width.

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

DOI： 10.19009/jjacg.33.5_359

researchmap

researchmap

Language：English   Publisher：TAYLOR & FRANCIS LTD  

Dislocation images in X-ray topography of protein crystals Such as tetragonal lien egg-white lysozyme crystals were analyzed. Not only extinction but also double contrast of dislocation images are clearly observed on the X-ray topographs. It should be noted that the observed image widths of the dislocation contrasts are much less than those calculated on the basis of the kinematical theory in X-ray topography, which has been successfully applied for inorganic crystals and organic crystals of small molecules so Far. Moreover, in tetragonal HEW lysozyme crystals, the rocking curve widths of the perfect crystal related to the kinematical theory are less than the measured ones by two orders of magnitude. This discrepancy is consistent with that in the image width of the dislocation contrast. From this correlation, it is suggested that the larger rocking curve width, or higher mosaicity, is mainly responsible for the observed image width in the grown crystals.

DOI： 10.1080/14786430500267752

Web of Science

Scopus

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

CiNii Books

J-GLOBAL

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

The rocking curve width of tetragonal lysozyme crystals were measured. Typical full width half maximum (FWHM) of the rocking curve of crystals grown from a pure lysozyme solution were 0.004-0.006°, while those crystals containing 5% lysozyme dimer were 0.006-0.010°. X-ray topography experiments revealed that dislocations existed in crystals containing lysozyme dimer. Point bottomed etch pits were observed in contaminated crystals, but hardly no deep pits were observed in pure crystals. These dislocations are one of the causes of rocking width broadening.

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

Longitudinal and transverse sound velocity of cross-linked tetragonal hen egg-white (HEW) lysozyme crystals was measured by ultrasonic pulse-echo method.

CiNii Books

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.11316/butsuri1946.59.444

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：English  

Longitudinal sound velocity of tetragonal hen-egg-white (HEW) lysozyme crystals was measured during air drying by ultrasonic pulseecho method. The sound velocity increases with exposure to open air and approaches a constant value. The maximum value is [Formula presented] that is about 1.6 times as much as that of original one before drying. In addition, the sound velocity clearly recovers to original one after immersing the dried crystal in solution. Therefore, the sound velocity in tetragonal HEW lysozyme crystals can be reversibly changed due to dehydration and rehydration. These changes in sound velocity are discussed in the light of water-mediated intramolecular and intermolecular interactions in the crystals. © 2004 The American Physical Society.

DOI： 10.1103/PhysRevE.69.051921

Scopus

PubMed

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

Longitudinal and transverse sound velocity of tetragonal hen egg-white (HEW) lysozyme crystals dried at 42% relative humidity (RH) was measured by ultrasonic pulse-echo method. Thus, six elastic constants of the dried tetragonal HEW lysozyme crystals were determined.

CiNii Books

researchmap

researchmap

researchmap

Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (bulletin of university, research institution)  

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

Tetragonal hen egg-white lysozyme crystals were grown by the solubility-gradient method. Laue topography using the synchrotron radiation was applied for the identifications of the imperfection of the grown crystals. Some defect images were clearly observed on the topographs.

DOI： 10.1107/S0909049503020417

Scopus

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Japanese Association for Crystal Growth (JACG)  

A new type of C_<60> needle-like crystal, or C_<60> 'nano' whiskers were grown by a liquid-liquid interfacial precipitation method. It was found that the growth of the nanowhiskers was promoted under illumination. From Raman soattering measurements, it is shown C_<60> moleoules in the pristine nanowhiskers are bonded by weak van der Waals forces. The rate of the photo-polymerization in C_<60> nanowhiskers is much faster than that in C_<60> bulk crystals.

CiNii Books

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

Orthorhombic hen egg-white lysozyme crystals were grown by the batch method. The largest grown crystal is about 18mm×6.6mm×4mm. X-ray topographs of those orthorhombic lysozyme crystals were taken by using white synchrotron radiation and some dislocation lines were observed in the topographs.

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：日本結晶成長学会  

Tetragonal hen egg-White lysozyme crystals were grown by the solubility-gradient method. Laue topography using the synchrotron radiation was applied for the assessment of the imperfection of the grown crystals. Some defect images were clearly observed on the topographs. The identifications of the defects are presented.

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：一般社団法人 日本物理学会  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Japanese Association for Crystal Growth (JACG)  

2, 3-dimethylnaphthalene crystals with large size and high quality were grown. from the melt by Bridgman method. Not only grown-in dislocations but also slip dislocations in the crystals were characterized by X-ray topography.

CiNii Books

researchmap

Language：Japanese   Publisher：The Japanese Association for Crystal Growth (JACG)  

N-methylurea crystals, which is one of a few nonlinear optical crystals for ultraviolet light, were grown from the melt by Czochralski method and their perfections were assessed by X-ray topography. The crystal defects, especially dislocations, were individually observed on the topographs, and characterized.

CiNii Books

researchmap

Language：Japanese   Publisher：The Japanese Association for Crystal Growth (JACG)  

Hen-egg white lysozyme crystals with tetragonal structure was grown by solibility-gradient method using NiCl_2 as a precipitant. Mechanical characteristics, i.e. stress-strain curve.Vickers microhardness, and cleavage, of the grown crystals were investigated.

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books

researchmap

Language：Japanese   Publisher：The Physical Society of Japan (JPS)  

CiNii Books