First principles modeling of the structural, electronic, and vibrational properties of Ni$_{40}$Pd$_{40}$P$_{20}$ bulk metallic glass

TL;DR

This study uses ab initio simulations to explore the structural, electronic, and vibrational properties of Ni40Pd40P20 bulk metallic glass, revealing key local structures and matching experimental spectra.

Contribution

It provides a first-principles model of Ni40Pd40P20 metallic glass, detailing its local atomic arrangements and validating results with experimental data.

Findings

Few to no P-P bonds in the structure

Presence of TTP and CSAP building blocks

Good agreement with experimental EXAFS and vibrational data

Abstract

The structural, vibrational, and electronic properties of Ni$_{40}$Pd$_{40}$P$_{20}$ bulk metallic glass have been studied using ${\it ab\,initio}$ molecular-dynamics simulations and total-energy optimization. Structural analyses of the resulting ${\it ab\,initio}$ models show the presence of few to no P-P bonds and two main building blocks, consisting of tricapped trigonal prism (TTP) and capped square anti-prism (CSAP) with P as the center of these blocks. The computed Pd and Ni K-edge spectra of extended x-ray absorption fine structure (EXAFS) are found to be in good agreement with experimental data. The configurational-average static structure factor and the generalized vibrational density of states are also observed to be in good agreement with experimental data.