Effect of intrinsic anharmonicity on the Adiatats (∂T/∂P)_S of NaCl

Abstract

NaCl-B1 phase is representative pressure stanndard, thus many types of experiments were conducted to constrain models of equation of state. Boehler (1981) obtained data of Adiabats up to 5 GPa, however no model of equation of state based on quasi-harmonic approximation can reproduce the data at high temperartures. Intrinsic anharmonicity effects to lower the Gruneisen parameter at high temperatures, thus we challenge to reproduce the data of Boehler using equation of state based on intrinsic anharmonicity theory. However, the intrinsic anharmonicity model results in a slight improvement. Rapid disappearance of intrinsic anharmonicity in small compression relates this results.