Compressional and shear-wave velocities of the polycrystalline CaGe O3 perovskite to 10 GPa

Compressional and shear-wave velocities and unit-cell volumes of orthorhombic CaGe O3 perovskite have been measured up to 10 GPa at ambient temperature using ultrasonic interferometry in conjunction with synchrotron x radiation. Fitting all velocity and unit-cell volume data to finite-strain equations yields the zero-pressure adiabatic bulk and shear moduli and their pressure derivatives KS0 =194.6 (11) GPa, G0 =109.5 (5) GPa, K S0 ′ =6.4 (2), G0′ =1.7 (1), with an rms misfit of 0.009 km s-1. From the data in the current study, we have observed no discontinuities or elasticity softening for either the bulk or shear moduli up to the peak pressure of 10 GPa.