Local Five-Fold Symmetry and Diffusion Behavior of Zr64Cu36 Amorphous Alloy Based on Molecular Dynamics**Supported by the National Basic Research Program of China under Grant No 2013CB733000, and the National Natural Science Foundation of China under Grant Nos 51271161 and 51271162.

Abstract

A molecular dynamics simulation is performed to investigate the relationship between the local five-fold symmetry and the diffusion behavior involved in the rapid solidification of a Zr64Cu36 alloy melt. The Voronoi polyhedron analysis indicates that the icosahedral clusters cannot explain the total amorphous structure, while the local fivefold symmetry shows more advantage in describing the relationship between the transition of the clusters and the diffusion behavior of Zr64Cu36 amorphous alloy. It is found that when the fraction of the local five-fold symmetry is less than 0.3, the diffusion coefficient increases significantly, and when the value exceeds 0.7, diffusion behavior is inhibited. The simulation provides a new viewpoint for understanding of the glass-forming mechanism.