Atomic Velocity Distributions and Diffusing Behaviors in a Nano-Alloy Cluster

Abstract

This paper studies the velocity distributions and diffusing behaviors of the atoms in a nano-alloy cluster. A series of ternary alloy clusters, Au50Cu25Ni25, and binary alloy clusters, Cu100−aNia are introduced in the molecular dynamics simulations. The velocity distributions of different types of atoms in both static and moving clusters are found to obey the Maxwell’s velocity distribution with the individual mass of atoms and the inner temperature of clusters. Furthermore, the velocity distribution of whole atoms of the cluster is obtained by synthesizing the velocity distributions of compositions in the cluster according to the proportions. The consistency of the atomic motions in a moving cluster is discussed by inspecting the backward velocities of atoms, which are correlated to the translational velocity and the inner temperature of the cluster. The diffusing behaviors of the atoms in a cluster are also investigated from a viewpoint of the interatomic interactions, i.e. Cu atoms enhance the activities of Ni atoms, or Ni atoms reduce that of Cu atoms in the alloy clusters.