IN-SITU STUDIES OF THE PROPERTIES OF MATERIALS UNDER HIGH-PRESSURE AND TEMPERATURE CONDITIONS USING MULTI-ANVIL APPARATUS AND SYNCHROTRON X-RAYS

Increased access to multi-anvil high-pressure devices interfaced to sy nchrotron Xray radiation sources has led to a new class of experiments . These new capabilities include (a) high-precision crystal structure determination and refinement from powder X-ray diffraction data; (b) t he determination of kinetic parameters and structure from time-resolve d diffraction data; (c) the determination of absolute pressures by the combined use of ultrasonic techniques at high pressures and temperatu res with simultaneous monitoring of X-ray diffraction; and (d) the det ermination of the strength and rheological properties of materials thr ough the monitoring of the relaxation of broadened diffraction peak wi dths in the presence of a well-characterized deviatoric stress field g enerated in the multi-anvil high-pressure apparatus.