Equations of state of MgO at high pressure and temperature

A synchrotron X-ray diffraction study on MgO has been done at simultaneous high pressure and temperature. The lattice parameter of MgO has been measur ed up to a static pressure of 6 GPa and a temperature of 1273 K, using a la rge volume pressure cell and energy-dispersive synchrotron X-ray powder dif fraction. The compression was made following six high-temperature isotherms . A Vinet equation of state was used to fit the experimental P-V-T data. Th e Vinet's model compares very well with the experimental data above the Deb ye temperature (760 K) and allows the use of MgO as an alternative internal pressure calibrant for experiments at high temperature.