Atomic mechanism of liquid-glass transition for Ca7Mg3 alloy.
Atomic mechanism of liquid-glass transition for Ca7Mg3 alloy.
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DOI：
10.1021/jp301576f
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
Z. Hou;Li-Xia Liu;Z. Tian;Rang-su Liu;Yu Shu;Jinguo Wang
中科院分区：
文献类型：
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作者：
Z. Hou;Li-Xia Liu;Z. Tian;Rang-su Liu;Yu Shu;Jinguo Wang
用分子动力学模拟方法研究了Ca(7)Mg(3)合金快速淬火过程中液-玻璃转变的原子机制。研究了液体-玻璃转变过程中结构、热力学和动力学性质的温度依赖关系。发现这些不同性质开始偏离平衡液体的起始温度是相同的，并且接近熔化温度T(M)。结构转变温度(T(G)(Str))和动力学转变温度(T(G)(Dyn))均高于量热转变温度(T(G)(Cal))，这与许多实验和计算机模拟结果是一致的。类固体和类液体原子由德拜-沃勒因子定义。结果表明，类固体原子具有较低的势能和较高的局域有序度。在类固体原子演化的基础上，系统地阐述了类固体原子在结构、热力学和动力学跃迁等方面的机制，与势能图景相一致。
The atomic mechanism of liquid-glass transition for Ca(7)Mg(3) alloy during the rapid quenching processes is studied by the molecular dynamics simulations. The temperature dependences of structural, thermodynamic, and dynamic properties during the liquid-glass transition have been investigated. It is found that onset temperatures where these different properties begin to deviate from the equilibrium liquid are identical and near the melting temperature T(m). The liquid-glass transition temperatures in structure (T(g)(Str)) and dynamics (T(g)(Dyn)) are identical and higher than the calorimetric one (T(g)(Cal)), which are consistent with many experiments and computer simulations. The solid- and liquid-like atoms are defined by the Debye-Waller factor. It reveals that the solid-like atoms hold lower potential and higher degree of local order. On the basis of the evolution of solid-like atoms, the atomic mechanisms in structure, thermodynamics, and dynamics transition are systematically elucidated, which are consistent with the potential energy landscape.