液态锗快速凝固过程中的分子动力学模拟

本文采用Stillinger-Weber势函数,对液态锗的快速凝固过程进行了分子动力学模拟,运用均方位移(mean square displacement,MSD),对相关函数(pair correlation function PCF),配位数(coordination number)和Wendt-Abraham关系...

Simulation Study of Liquid Ge During Rapid Cooling Solidification

A computer simulation tracking study for the rapid solidification processes of liquid metal Ge system has been performed by molecular-dynamics calculations using the Stillinger-Weber potential.The mean squared displacement,pair correlation function g(r) curves,coordination number and Wendt-Abraham ratio have been used to analyze the variations of microstructures during the solidification process.The pair correlation function obtained from this simulation is in good agreement with the experimental results,suggesting that the Stilinger-Weber potential is useful for analyzing Ge.The melting point of Ge is about 2100 K,as monitored by the mean-squared displacements.We can see from the g(r) curves at different temperatures that the fist-peak gradually becomes higher and sharper with the temperature decreasing,and the second-peak of g(r) gradually splits into two small peaks with a lower front sub-peak and a higher behind one.The solidification occurs in the temperature range 1200-600 K,and the glass transition temperature Tg is about 646 K.