Vibrational properties of phonons in random binary alloys: An augmented space recursive technique in the k-representation

TL;DR

This paper introduces an augmented space recursive method for analyzing phonon vibrational properties in random binary alloys, explicitly accounting for various types of disorder to improve accuracy and computational efficiency.

Contribution

The paper presents a novel augmented space recursive technique in the k-representation that explicitly includes diagonal, off-diagonal, and environmental disorder for phonons in alloys.

Findings

Accurate spectral functions and dispersion curves for studied alloys.

Good agreement with experimental data and ICPA results.

Demonstrates the method's efficiency and accuracy in complex disordered systems.

Abstract

We present here an augmented space recursive technique in the k-representation which include diagonal, off-diagonal and the environmental disorder explicitly : an analytic, translationally invariant, multiple scattering theory for phonons in random binary alloys.We propose the augmented space recursion (ASR) as a computationally fast and accurate technique which will incorporate configuration fluctuations over a large local environment. We apply the formalism to $Ni_{55}Pd_{45}$, $Ni_{88}Cr_12}$ and $Ni_{50}Pt_{50}$ alloys which is not a random choice. Numerical results on spectral functions, coherent structure factors, dispersion curves and disordered induced FWHM's are presented. Finally the results are compared with the recent itinerant coherent potential approximation (ICPA) and also with experiments.