Impact of Scattering on Phonon Behavior of Alloys

TL;DR

This paper investigates how scattering affects phonon behavior in alloys by using DFT calculations, comparing methods, and analyzing the impact of mass and force-constant fluctuations on phonon properties.

Contribution

It introduces a detailed comparison of WDM and supercell approaches for phonon calculations and examines scattering effects in specific intermetallic alloys.

Findings

WDM approach effectively calculates phonon dispersions and densities of states.

Mass and force-constant fluctuations significantly impact phonon behavior.

Comparison shows consistency between WDM, supercell, and neutron scattering results.

Abstract

The lattice dynamics of Cu3Au, Ni70Pt30, Pd90Fe10, and Pd96Fe04 intermetallic is studied using the DFT calculations. We calculated the phonon dispersions and phonon densities of states along two high symmetry paths of the Brillouin zone by Weighted Dynamical Matrix (WDM) approach. We also compared the results with the supercell approach and inelastic neutron scattering. Furthermore, we calculated the impact of mass and force-constant fluctuations on the Cu3Au and made a comparison with both WDM and supercell approaches results. The averaged first Nearest Neighbor (1NN) force constants between various pairs of atoms in these intermetallic structures are obtained from the WDM approach.