Modern X-ray spectroscopy 6. Using X-rays to probe phonons. Mainly in disordered materials

Recently, studies of phonons by inelastic x-ray scattering (IXS) technique with a high energy resolution of meV order have considerably developed by using an excellent technique for utilizing third-generation synchrotron radiation facilities and recent progress of semiconductor technique. In this article, the history of studies of phonons using x-rays, the principle of IXS and the advantage (disadvantage) of IXS are briefly reviewed by comparing to inelastic neutron scattering, and an excellent IXS spectrometer installed at the beamline BL35XU of the SPring-8 is introduced. Finally, examples of recent studies performed at BL35XU/SPring-8 are introduced in many disordered systems. (author)