Structural characterization of Mg 65Cu 25Y 10 metallic glass from ab initio molecular dynamics

Abstract

Ab initio molecular dynamics simulation (AIMD) was performed on the structural evolution of Mg 65Cu 25Y 10 alloy from 2000 K to 300 K. Pair correlation functions (PCFs), coordination numbers (CNs) and structure factors (SFs) of this glassy alloy were characterized. With the temperature decreased, the first peaks of both PCF and SF become narrower and higher, and shift to higher displacement or higher scattering vector. At the room temperature, the second peaks of both PCF and SF curves occur splitting, and the height of first peak of partial PCF for heterogenic atomic pairs is larger than that for homogenic atomic pairs. The generalized coordination numbers in this alloy are in good agreement with the results calculated by using efficient atomic packing model, which approves the atomic configuration of this alloy is in terms of dense packing. It was also found that the shape of both PCF and SF, and the CNs occur distinct change around 750 K.