铁磁性物质Ni的液态结构的分子动力学模拟

The Molecular Dynamics Simulation of Magnetic Substance Ni

用分子动力学模拟方法在1873～300K对液态Ni的微正则系统进行了模拟研究，模拟采用EAM相互作用势对时间和空间的平均，得到了不同温度下Ni的双体分布函数及原子组态变化的重要信息，并利用键对分析技术对模拟结果作了深入讨论。

By means of constant-pressure molecular dynamics simulation technique, a series of semulations of glass transition of Ni have been performed. The atomic interaction via semiempirical embedded taom method many-body potential. The pair distributed function, the orientation order parameters and pair analysis technique are used to reveal the structural features of liquid metal and the structural evolution during rapid solidification. The glass transition temperature of liquid Ni are determined when the cooling rate is 2.8×1013K/s. The sedation result tell us that the order degree of the liquid Ni increases with the temperature decreases, and the glass transition of liquid Ni is 1010K or so. It is obvious that the sedation pair distributed function g(r) of Ni is in good agreement with the experiment data, which means the EAM can predict the liquid structure and glass transition of Ni correctly. The heights of the pair distributed function g(r) become larger and larger with the temperature decrease, which means the order degree of the liquid Ni has been strengthened and the coordination number become larger than high temperature, The orientation order parameter W6 is nearly equal to -0.1698 when the temperature is low, which means the icosahedra exists in the low temperature liquid. The orientation order parameters Q6 and W6 are very important parameters to detect the liquid structure. The various bonded pairs in liquid Ni are the basic units when the liquid Ni solidifies. It gives us a dear micro-picture of liquid Ni and makes us understand it deeply.