Structural Analysis with Advanced X-ray Techniques
Dopants play an important role in various functional materials,
which is manifested, for example, in the significant change in the electrical properties of semiconductors with doping.
For clarifying the origin of such functions,
it is important to understand the site of dopants and the local arrangement of the surrounding atoms.
Our research is based on the advanced structural analysis technique called x-ray fluorescence holography (XFH).
XFH provides 3D atomic configuration around dopants, which is difficult to obtain with conventional techniques.
This information is essential for obtaining the atomic-level understanding on the role of dopants,
which provides insight into designing novel functional materials. We are applying XFH to various materials,
such as shape-memory alloy, thermoelectric materials, and lightweight Mg alloy.
In addition, we are working on the phonon observation with inelastic x-ray scattering, neutron holography,
inverse photoelectron holography, evaluation of thin films with x-ray reflectivity measurements,
structural analysis of electrolyte in rechargeable batteries, and the single crystal growth with Bridgeman method.
Development of New Manufacturing Processes of Green Materials for Social Infrastructure
Saving of natural resources and energy, global environment, recycling of waste, etc.
are becoming increasingly important today. In these circumstances, we are challenging untrodden research areas such as
effective utilization of energy and natural resources in the material manufacturing process,
promotion of recycling of the resources and a new material creation process for using the ultrasound vibration.
For the highly efficient material processing considered in the environment and recovering,
recycling, detoxifying of by-products, the following researches, collection of valuable metals
by a dry processing of discarded nickel hydride battery and neodymium magnet,
removal of magnesium by chlorination processing of wasted aluminum and hydrogen production by a reaction of molten zinc
and water vapor, are conducted. Furthermore, for the material processing of ultrasound,
the effect of ultrasound on agglomeration and removal for dispersed
particles, heat and mass transfer in molten metal are also investigated.