液态Ni原子团簇演变的计算机模拟

采用常温常压分子动力学模拟技术,模拟了液态Ni中原子团簇在快速凝固条件下的演变过程,模型采用TB作用势.采用偶分布函数、键对和多面体等结构参数来描述快速凝固条件下团簇种类和数量的变化,并将团簇结构可视化.在2 000 K下,液态Ni中团簇数量较少,由一定数量的1551、1441及1661键对所形成的缺陷二十面体构成;在快速冷却条件下,团簇的数量随温度的降低不断增加,且出现由12个1551键型所形成的完整二十面体团簇,体系最终形成了由二十面体和缺陷二十面体团簇网络所组成的非晶结构.

Computational simulation on the evolution of liquid Ni atom clusters

A series of simulation on the evolution of atom clusters in liquid Ni during rapid solidification have been performed under constant temperature and constant pressure by molecular dynamic simulation technique. TB potential function has been used to describe the interaction between atoms. The structure parameters such as pair correlation function, bonded pairs and polyhedra clusters have been adopted to characterize the temperature dependence of the type and number of clusters during rapid cooling process, and cluster structure obtained by the simulation can be converted to three-dimension graphical interface. the number of clusters in liquid Ni is small and all are made up of diicosahedron; During the rapid cooling process, the number of clusters increases rapidly with the decrease of temperature, and the icosahedra exists at low temperature. The network consists of the icosahedra and diicosahedra clusters can be formed in the amorphous system.'