非晶Cu在晶化过程中的分子动力学模拟

运用分子动力学模拟的方法, 采用紧束缚势函数, 研究了非晶Cu在升温条件下的晶化行为, 分析了系统能量、体积、双体关联函数和局部结构的变化, 并结合键对分析方法计算了不同弛豫时间下典型短程有序结构的分布. 结果表明, 在非晶Cu升温的最初阶段, 原子运动未必造成短程结构的进一步规则化; 结构转变初期,首先发生1431和1541键向1421键的转变, 1421键型数量在400 K以上则基本呈现直线上升的趋势, 接近600 K时达到最大值; 此后1421键的数量随温度的上升而下降, 熔化时其数量急剧减少.

MOLECULAR DYNAMICS SIMULATION OF CRYSTALLIZATION PROCESSES FOR AMORPHOUS Cu

The crystallization processes for amorphous Cu were investigated by the molecular dynamics technique with the tight--binding potential, and the changes of pair correlation distribution function, total energy and volume of the system during the processes were analyzed, meanwhile the static structural information on the pair distribution functions and distribution of the coordination numbers were obtained. The results show that the movement of Cu atoms has slightly effect on the short--range ordered structures at the initial heating period of amorphous Cu, 1431 and 1541 bonds change firstly into 1421 bond at the first stage of structural transformation, and the number of 1421 bond increases at above 400 K and gets its maximum at about 600 K, then decreases with temperature increasing and has a quick decline at melting point.