金属Cu晶化与玻璃化行为的分子动力学模拟

采用分子动力学模拟的方法,运用Mishin镶嵌原子模型,研究了液态Cu在不同冷却条件下的晶化与玻璃化行为.记录了系统能量、体积、径向分布函数及公共近邻的变化,并在0K分析了弛豫后系统原子内能、原子Voronoi体积及原子应力等热力学性质的分布情况.模拟结果表明,在较慢的冷却条件下,液态Cu形成晶态;在较快的冷却条件下,液态Cu形成非晶态.与晶态Cu比较,金属玻璃Cu有较高的能量和较大的体积,其内部晶格畸变导致了本征应力的存在.

Molecular Dynamics Simulation of Crystallizing and Vitrifying Processes for Metal Cu

A series of simulations of the crystallization and vitrification processes for metal Cu were carried out by means of the molecular dynamics technique. The radial distribution function, common neighbors, internal energy and volume of the system were recorded during the processes. The atomic internal energy, atomic Voronoi volume and atomic stress field of the relax system were analyzed at zero temperature. The interaction between atoms in the system is described using the embedded atom potential as proposed by Mishin. The simulation results show that crystalline and non-crystalline phases form at lower and higher cooling rates respectively. In comparison to nanocrystals, it is found that metallic glass has higher internal energy and larger volume. The intrinsic stress field is induced by distortion of the lattice.