Comparative Study of Analytical Models of the Gruneisen Parameter of Metals as Function of Pressure
Commonly used Gruneisen parameter (γ) models only hold accurate in limited regimes making them inapplicable for use over wide temperature-pressure conditions. The accuracy of these analytical models of γ and of the thermal expansion of solids are of particular interest as these are considered proxies for quantifying anharmonicity, which may be a significant contribution to the thermal pressure at high temperatures. This work reviews various definitions of γ and their relations to the equations of state and apply them to two simple metals: Tantalum (Ta) and Copper (Cu), for which a high body of experimental data exists. Classical Molecular Dynamics simulations are employed in both constant temperature and constant pressure formalisms to obtain pressure and volume data over wide temperature-pressure conditions. We discuss the dependence of γ with pressure focusing on Cu and Ta as examples and compare our results with predictions from commonly used analytical models of γ as well as experimental data.
Materials science|Computational physics|Engineering
Garcia Amparan, Celia, "Comparative Study of Analytical Models of the Gruneisen Parameter of Metals as Function of Pressure" (2019). ETD Collection for University of Texas, El Paso. AAI22620615.