1205.1077 (Shibing Wang et al.)

Pressure-induced symmetry breaking in tetragonal CsAuI3    [PDF]

Shibing Wang, Shigeto Hirai, Maxwell C. Shapiro, Scott C. Riggs, Theodore H. Geballe, Wendy L. Mao, Ian R. Fisher

Results of in situ high pressure x-ray powder diffraction on the mixed valence compound Cs2Au(I)Au(III)I6 (CsAuI3) are reported, for pressures up to 21 GPa in a diamond anvil cell under hydrostatic conditions. We find a reversible pressure-induced tetragonal to orthorhombic structural transition at 5.5-6 GPa, and reversible amorphization at 12-14 GPa. The high pressure orthorhombic structure comprises two distinct Au sites, in contrast to previous assumptions based on measurements probing the associated pressure-induced valence transition Au(I)+Au(III) --> 2Au(II).

View original: http://arxiv.org/abs/1205.1077