Three-body effect on the lattice dynamics of some fcc d-band metals


Akgun I., UĞUR G. , Gunen A., Civi M.

NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS, vol.19, no.6, pp.787-796, 1997 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 6
  • Publication Date: 1997
  • Title of Journal : NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS
  • Page Numbers: pp.787-796

Abstract

In the present analysis, the interaction system of an fcc d-band metal is considered to be composed of two-body and three-body parts. We use a new three-body potential developed by Akgun and Ugur to deduce the contribution of many-body forces to the dynamical matrix of the fcc structure. Two- and three-body potentials are first used, as an application to investigate the dynamical behaviors of fcc d-band metals, Ni, Pd, Cu and Ag. The parameters defining the two- and three-body potentials for the metals are evaluated from knowledge of the equilibrium pair energies, bulk modulus and total cohesive energies of the metals, following a procedure given by Akgun and Ugur. In this scheme the input data is independent of phonon frequencies and elastic constants of the metals. Finally, the phonon frequencies of the metals along the principal symmetry directions are computed using the calculated radial, tangential and three-body force constants. The theoretical results are compared to experimental phonon dispersions. The agreement shows that the proposed potentials and crystal model provide a reasonable description of the lattice dynamics of fcc d-band metals.