Lattice dynamics and inelastic nuclear resonant x-ray scattering

Measurements of thermal and elastic properties of materials, such as the ph onon density of states, specific heat, and speed of sound, by a new xray sc attering technique are presented. Inelastic nuclear resonant scattering of x-rays produced from new electron storage rings, coupled with advances in h igh-energy-resolution crystal optics, and fast detectors have enabled the d evelopment of a new method of analysing the energy loss in a scattering pro cess with a resolution of 10(7) or better in the x-ray region of 6-30 keV. Some unique aspects such as element (isotope) selectivity, the amount of ma terial needed for analysis (nanograms), and the physical size to which x-ra ys can be focused (5 mum or better) favour this approach over the more esta blished techniques of neutron scattering and Mossbauer and Raman spectrosco py. Applications to several unique cases-for example, those of multilayers. and high pressure-are discussed.