Fig.1. (Left) An image of electron orbital ordering at atomic sites observed in
rare-earth metallic compounds.
(Right) A schematic view of spin molecule in the pyrochlore lattice.
Aim of our research is to discover and to understand various physical phenomena of materials; superconductivity, metal-insulator transition, and so on. Key providing these phenomena is interaction between electrons which carry degrees of freedom of charge, spin, and orbital. Our main techniques for the investigation of electronic systems are neutron and x-ray scattering, which reveal precisely the microscopic structure of electronic states and crystal structures. In addition, we search for typical materials exhibiting the attractive properties, grow high quality crystal samples, and measure fundamental properties. We also make an effort to develop new scattering instruments and experimental methods in order to identify various materials structures.
We own and operate a triple-axis neutron spectrometer with polarization analysis option (TOPAN) at the research reactor JRR-3 in Japan Atomic Energy Agency (Tokai, Ibaraki). We also use pulsed neutron scattering instruments installed at Materials and Life Science Experimental Facility in J-PARC. Sometimes, we used other neutron facilities all over the world. X-ray scattering experiments are performed at four-circle spectrometers with a rotating anode x-ray source in our university laboratory as well as at various synchrotron radiation facilities such as Photon Factory (KEK Tsukuba) and SPring-8 (JASRI Harima).
Fig.2. (Left) Neutron spectrometer TOPAN. (Right) Four-circle X-ray diffractometer in univerisity laboratory.
Our recent research activities cover magnetic and multipolar ordering phenomena in rare-earth based compounds, heavy fermion systems, electronic state given by low-energy phonon modes, highly frustrated magnetic oxides, spin molecule, and so on. In order to make a progress in the study of these materials, we make a lot of efforts to synthesize high quality samples of typical materials.