Pressure-volume relationships of some solids based on double potential energy functions

Abstract

Abstract We present an analysis for the pressure-volume relationship of substances viz. Neon, Argon, Aluminum, Copper, Lithium Hydride, and Magnesium Oxide using interatomic potential functions due to Morse, Rydberg, and Davydov. The formulations for P-V relationship have been obtained using these potential functions. The results for pressure as a function of volume are determined up to a range of V/(V_0=0.5) for each solid. The results are mapped with the values obtained from the Shanker equation and the Hama-SuitoEOS. The relationship between P and V through different equations of state(EOS) for different solids depends on the values of K_(0 )as well as K_0^’. A material would be more incompressible if both K_(0)and 〖K〗_0^’are high. For example in case of Cu, K_(0 )is somewhat less than that for MgO but 〖K〗_0^’ is larger for Cu than that for MgO. This makes Cu to be more incompressible than MgO. This is evident from the results which reveal P = 620GPa for Cu, and P = 430GPa for MgO both at V/V_0 = 0.5, the maximum compressions.