Atomistic study on the difference in thermo-mechanical properties of metal glass and amorphous alloy

为了在原子尺度上考察非晶态材料的几何和力学结构的基本特征，对恒压条件下单组分原子体系的变形过程进行了分子动力学模拟。通过对径向分布函数和均方位移的Voronoi多面体分析和计算，研究了该过程中原子结构特征特征的转变。结果表明，得到的准稳定原子结构呈径向分布，第二峰分成两个尖端，几乎是包含5个以上五角面的Voronoi多面体。多面体的体积与应力的第一不变量和具有(0 0 12 0)型多面体的原子之间有很强的相关性。

To examine the fundamental characteristics of the geometric and mechanical structure of amorphous material on an atomic scale, molecular dynamics simulations for deformation process of a single-component atomic system are carried out under the constant-pressure condition. Voronoi polyhedron analysis and calculation of the radial distribution function and the mean square displacement are performed to study the transition of characteristic features of the atomic structure in the process. It is proven that the obtained quasi-stable atomic structures have a radial distribution with the second peak separated into two apexes and are almost the Voronoi polyhedron which contains more than 5 pentagonal planes. Strong correlation between the volume of the polyhedron and the first invariant of the stress is recognized and the atom which has the (0 0 12 0)-type polyhedron.