Reverse Monte Carlo Simulations and Raman Scattering of an Amorphous GeSe$_4$ Alloy Produced by Mechanical Alloying

TL;DR

This study combines Reverse Monte Carlo simulations and Raman scattering to analyze the short and intermediate range order of an amorphous GeSe4 alloy produced by Mechanical Alloying, revealing structural differences from other preparation methods.

Contribution

It introduces a combined RMC and Raman approach to characterize the atomic structure of mechanically alloyed GeSe4, highlighting unique structural features.

Findings

High number of Se-Se pairs in the first shell

Presence of Se-Se bridges connecting tetrahedral units

Structural differences compared to alloys made by other techniques

Abstract

The short and intermediate range order of an amorphous GeSe$_4$ alloy produced by Mechanical Alloying were studied by Reverse Monte Carlo simulations of its x-ray total structure factor and Raman scattering. The simulations were used to compute the $G^{\text{RMC}}_{\text{Ge-Ge}}(r)$, $G^{\text{RMC}}_{\text{Ge-Se}}(r)$ and $G^{\text{RMC}}_{\text{Se-Se}}(r)$ partial distribution functions and the ${\cal S}^{\text{RMC}}_{\text{Ge-Ge}}(K)$, ${\cal S}^{\text{RMC}}_{\text{Ge-Se}}(K)$ and ${\cal S}^{\text{RMC}}_{\text{Se-Se}}(K)$ partial structure factors. We calculated the coordination numbers and interatomic distances for the first and second neighbors and the bond-angle distribution functions $\Theta_{ijl}(\cos\theta)$. The data obtained indicate that the structure of the alloy has important differences when compared to alloys prepared by other techniques. There are a high number of Se-Se pairs in the first shell, and some of the tetrahedral units formed seemed to be connected by Se-Se bridges.