In an attempt to obtain reliable first-principles phonon dispersions of random alloys, we have developed a method to calculate the dynamical matrix, with respect to the wavevector space of the ideal lattice, by averaging over the force constants of a special quasi-random structure. Without additional approximations beyond standard density functional theory, the present scheme takes into account the local atomic position relaxations, the composition disorder, and the force constant disorder in a random alloy. Numerical results are presented for disordered Cu3Au, FePd, and NiPd and good agreement between the calculations and the inelastic neutron scattering data is observed.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics