High-brilliance X-ray system for high-pressure in-house research: applications for studies of superhard materials

Newly installed, at Bayerisches Geoinstitut, X-ray system consists of three major components: RIGAKU FR-D high-brilliance source, Osmic's Confocal Max-Flux optics, and SMART APEX 4K CCD area detector. We tested the system for single-crystal structural studies on example of garnet, Co3Al2Si3O12, for powder diffraction analysis on example of a small sample of boron carbide, B4C, recovered after treatment in a multi-anvil apparatus, and for in situ experiments at high pressure on example of FeO compressed in a diamond anvil cell to > 100 GPa. In all the cases, the system demonstrated its reliability and provided results comparable with those obtained using the best currently available instruments. Using a new X-ray system, we measured the compressibility of superhard nanocrystalline diamond at pressures up to 26 GPa and found it to be extremely incompressible with K-T = 488( 4) GPa, K' = 3.1(2), and V-0 = 3.401( 6) cm(3)/mol.