冷却过程中Pd923 团簇的结构转变研究

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。

Structural changes of Pd923 clusters during freezing

The structural transitions of Pd923 clusters during the different quenching processes were studied using molecular dynamics simulations. This work gives the structure properties including the variations of pair-correlation function, bond pairs and bond orientational order parameters with temperature in two rapid quenching processes. Our results indicate that the liquid Pd923 is frozen into amorphous structure at 300 K during the cooling rate 50 K/ps. While the liquid Pd923 is transformed to hexagonal close-packed (hcp) phase at the temperature 100 K during the cooling rate 0.1 K/ps.