冷却过程中Pd923团簇的结构转变研究

摘要

The structural transitions of Pd 923 clusters during the different quenching processes were studied using molecular dynamics simulations.This work gives the structure properties including the variations of pair -corre-lation function , bond pairs and bond orientational order parameters with temperature in two rapid quenching processes.Our results indicate that the liquid Pd 923 is frozen into amorphous structure at 300 K during the cooling rate 50 K/ps.While the liquid Pd 923 is transformed to hexagonal close -packed ( hcp) phase at the temperature 100 K during the cooling rate 0.1 K/ps.%本文利用分子动力学模拟方法，研究了钯团簇在不同冷却条件下形成晶体及非晶的过程.利用平均原子体积、双体分布函数、键对分析和键序参数方法研究了微观局域结构随温度的变化关系.研究发现：在50 K／ps冷却过程中，液态Pd923团簇在1000 K发生玻璃化转变，在100 K下形成非晶结构；而在0.1 K／ps冷却过程中，液态Pd923团簇发生结晶，并最终形成六角密排（ hcp）晶体结构．