Ultrasonic measurements of single-crystal gold under hydrostatic pressures up to 8 GPa in a Kawai-type multi-anvil apparatus

摘要

Ultrasonic measurements were conducted on single-crystal gold at ambient condition and hydrostatic pressures up to 8 GPa at room temperature in a Kawai-type multi-anvil apparatus. The P-wave velocities measured at high pressures were in good agreementwith Daniels and Smith's ultrasonic study. The three independent elastic constants of gold at ambient condition were determined to be Cn=192.7 GPa, C_(12)=162.9 GPa, and C_(44)=42.4 GPa. On the basis of an analysis of previous elastic data and the present ultrasonic data, the pressure derivatives of three elastic constants were estimated to be C'_(11) = 7.12, C'_(12) = 6.24, and C'_(44) = 1.82. The calculated values of isothermal bulk modulus (K_(T0)) and its pressure derivatives (K'_(T0)) are K_(T0) =166.44 GPa and K'_(T0)= 6.56. This indicates that Anderson et al.'s model of equation of state of gold might underestimates pressure about 1 GPa at pressure around 23 GPa and ambient temperature. Our results explained the discrepancies among the modelsof equation of state of gold proposed previously.