Theoretical calculations of high-pressure melting curves of five metals
Theoretical calculations of high-pressure melting curves of five metals
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DOI：
10.7498/aps.61.016401
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发表时间：
2012-01
期刊：
影响因子：
--
通讯作者：
Xing Jie;Xiang Shikai;Cai Ling-Cang
中科院分区：
文献类型：
--
作者：
Xing Jie;Xiang Shikai;Cai Ling-Cang
在基于对电位的金属平均场模型中，采用从头算方法确定了势函数和未知参数。利用势函数构造的平均场，计算了金属Al、Cu、Ni、Na和K原子在熔点处的自由振动体积。结果表明，普遍采用的熔化曲线中原子的自由振动体积与原始胞体体积之比为常数的假设是不正确的。提出了一种比值模型，该模型可以得到更精确的熔化曲线结果。
Ab-initio calculation method is employed to determine the potential functions and the unknown parameters in pair-potential-based mean filed model for metals. Using the mean fields constructed from the potential functions, the vibration free volumes of atoms of metals Al, Cu, Ni, Na, and K at melting points are evaluated. The results indicate that the widely used hypothesis that the ratio of vibration free volume to the primitive cell volume of atoms in melting curve is a constant, is not correct. We provide a ratio model which can be usd to obtain much more accurate results of melting curve.