Fundamental studies on X-ray, neutron, and electron diffraction, in particular intended for the development of new methods to solve the structure of surfaces, interfaces, and nano structures by using interference phenomena. Aiming to solve the phase problem in surface X-ray diffraction, we have developed new methods, such as a direct imaging of interface atoms from measured X-ray diffraction intensities, a characterization of meso-scopic range strain field utilizing multiple X-ray diffraction phenomenon, and X-ray fluorescence holography. These methods are applied for such as surface quasi-one dimensional metal, metal silicides, organic films. A recent topic is the development of a new method for quick measurement of surface X-ray diffraction profile aiming for time-resolved measurements of dynamic phenomena at surface and interface, that is collaborated with other researchers.
Electron density map of the one-dimensional structure of the Au-Si(553) surface, reconstructed from measured X-ray diffraction data by using a phase and amplitude retrieval algorism.
Bi thinfilm/Si(111) interface structure directly reconstructed from measured x-ray diffraction data.
A method for measuring the specular X-ray reflectivity with millisecond time resolution: W. Voegeli, T. Matsushita, E. Arakawa, T. Shirasawa, T. Takahashi and Y. F. Yano, J. Phys.: Conf. Ser.425 (2013) 092003(1-4).