采用改进分析型嵌入原子方法(MAEAM),对铌、钨晶体的(001)面预熔和熔化过程进行分子动力学模拟。通过计算不同温度的原子位置、层原子密度、层结构因子、径向分布函数等物理量,研究(001)面的微观结构随温度的变化。结果表明,(001)面在低于其完整晶体的熔化温度出现预熔。另外,通过将该面预熔摩尔分数对温度进行拟合发现,可以近似地预测(001)面的预熔过程。
Using the modified analytic embedded-atom method (MAEAM), the molecular dynamics (MD) simulation was performed to study the premelting and melting behavior of (001) plane of niobium and tungsten. The physical properties including the atomic positions, the layer atomic density and the layer structure factor were calculated to disclose the relations between their microstructures and temperature. The results indicate that there are some quasiliquid layers on plane (001) at some temperature below the melting points of the prefect crystals. In addition, the premelting mole fraction of the surface of these two metals is fitted with the corresponding temperature to obtain a relational expression which is able to forecast the disordering progress of this surface.