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HOME > プロフィール > ロク シンガプリゲ ロシャンタ クマーラ

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研究内容

Keywords

Nanoparticles, Thin films, Amorphous, Synchrotron X-rays, X-ray diffraction, X-ray absorption fine structure spectroscopy, hard X-ray photoelectron spectroscopy , pair distribution function (PDF) , reverse Monte Carlo (RMC)

1). Characterization & computer simulation studies on transition metal nanoparticles for catalysts by high-energy X-ray diffraction coupled to pair distribution function (PDF) and reverse Monte Carlo (RMC) modelling method, extended X-ray absorption fine structure spectroscopy (EXAFS), X-ray absorption near edge structure (XANES) and hard X-ray photoelectron spectroscopy (HAXPES). 2). Synthesis, characterization & computer simulation studies of chalcogenide semiconductor glasses and melts by means of X-ray and Neutron Diffraction and EXAFS. 3). Characterization of studies on oxide thin films and amorphous thin films, by high-energy X-ray diffraction, EXAFS, anomalous X-ray scattering (AXS), and RMC method. 4). Synchrotron X-rays techniques; high resolution powder XRD, thin films XRD , high-energy XRD, small angle X-ray scattering (SAXS), AXS, EXAFS, XANES and HAXPES. 5). The correlation between functional physical properties and characteristics structure of condensed matters.

researchPicture

My current research focuses on characterization of nanomaterials by utilizing synchrotron X-rays. Nanotechnology, the creation of functional materials, device, and system through the control of nanoscale materials, has recently become one of most active research field. Particle with diameters in the range of 2 to 100 nm, called nanoparticles (NPs), have become a major interdisciplinary area of research during recent decades due to various applications including fuel-cell electrocatalysts and automobile exhaust gas catalysts. Because catalytic reactions occur at the surface, nanosized metal catalysts are typically used in catalysis to improve the catalytic efficiency, by increasing the surface-to-volume ratio. Recently, the Kitagawa group at Kyoto University has reported the structural identification of novel fcc-type Ru NPs and the size dependency of their more efficient catalytic activity than conventional hcp-type Ru NPs. However, the catalytic properties of NPs are strongly dependent on their atomic-scale structure, which is difficulty determined by conventional powder X-ray diffraction. In collaboration with Kitagawa group, I have previously developed a method to investigating three-dimensional atomic-scale structure of Ru nanoparticles by using HEXRD techniques coupled with pair distribution function (PDF) and reverse Monte Carlo (RMC) modelling method [Phys. Chem. Chem. Phys., 2016, 18, 30622-30629]. The RMC simulation of the atomic-scale structure of spherical particle without applying periodic boundary conditions allows the testing and refining of structure models based directly on diffraction data of spherical like nanoparticles with free surface and inhomogeneities in the atomic ordering.

出版物2004年以降のNIMS所属における研究成果や出版物を表示しています。

論文
会議録

所属学会

The Japan Society of Applied Physics , Crystallographic Society of Japan , International X-ray Absorption Society , European Neutron Scattering Association

第二期開発予定
第二期開発予定

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