Atomic structure of Cu60Ti20Zr20 metallic glass under high pressures

Abstract

During the rapid cooling process, the atomic structure of the Cu60Ti20Zr20 ternary alloy under external pressure was investigated by molecular dynamics simulations using the embedded atom method potential. The effect of the pressure was discussed in detail by using a variety of analysis methods. Glass transition temperature determined by the modified Wendt-Abraham parameter was found to increase with increasing pressure. It was observed that the calculated total (or partial) pair distribution function and structure factor are in good agreement with the experimental x-ray data (with the ab-initio molecular dynamics results). The bond angle distributions of Cu-centered triplets were more consistent with ideal icosahedral clusters than that of Ti- and Zr-centered triplets. The dominant clusters for all pressures were icosahedral-like clusters that were not much affected by pressure. In addition to the bonds between Cu–Zr pairs shortening more easily under high pressure than other pairs, it is found that the Cu60Ti20Zr20 glassy alloy remained stable under pressure and its topological and atomic structures did not change much with pressure.