2010 年 20 巻 3 号 p. 262-268
Simultaneous elastic wave velocity and in situ synchrotron X-ray measurements enable us to determine absolute pressure self-consistently without using other pressure scales. Here I show a case study for MgO up to a volume reduction V/V0 of ∼0.9 (up to 23.6 GPa in our P-V-T relation of MgO) and at temperatures between 300 and 1650 K using a multi-anvil apparatus. The resultant adiabatic modulus and unit-cell volume led to the first self-consistent P-V-T relation of MgO, which reproduces the existing pressure-scale-independent data set. This paper focuses on the analytical procedure to determine self-consistent P-V-T relation from elastic wave velocity and unit-cell volume data.