Gasketing optimized for large sample volume in the diamond anvil cell: first application to MgGeO₃ and implications for structural systematics of the perovskite to post-perovskite transition

Improved post-perovskite structure models of MgGeO₃ (Cmcm) are obtained via development of a new graphite gasket for the diamond anvil cell which increases the volume of sample and quality of diffraction data at pressures near 100 GPa. These models agree with a structure survey supporting a new method for estimating the Clapeyron slope between perovskite (Pbnm) and post-perovskite structures of MgSiO₃.