Pressure-Dependent Thermal Expansion Coefficient by a Diamond Anvil Cell.

A thermal expansion coefficient (αp) is an essential thermophysical quantity for high pressure research. The thermal expansion coefficient is the volume change over temperature in an isobaric heating process. Although isobaric heating processes for diamond anvil cell (DAC) have been conducted by keeping the pressure constant during heating, pressure determination at high temperature high pressure is debatable for decades long. In this paper, a revertible heating/cooling approach is presented, while its pressure determination at high temperature high pressure is not required. A pressure-dependent thermal expansion coefficient of MgO at 9.5 GPa by revertible heating/cooling was determined by a DAC and its result matches with the one collected by large volume press, whose isobaric heating was conducted by manually adjusting its load/pressure. [ABSTRACT FROM AUTHOR]