The applicability of the modified Morse-Potential function for some cubic crystals

Özet

The Modified Morse-Potential has been applied to a number of cubic metals. The parametres in potential are determined by using the lattice parameter, bulk modulus, and cohesive energy for various m values. By using this potential, second and third-order elastic constants, pressure derivatives of the effective second-order elastic constants and bulk modulus, Grüneisen parameter for some cubic metals, and the phonon frequencies for copper are calculated. They are also compared with those obtained using the Morse-Potential, and with the existing experimental data. It is seen that for the elastic constant, the results obtained from the two potentials are not very different, but a significant improvements are obtained for different m values, especially, for m=3.00-3.50 (for fcc).