论文标题
通过包含热空缺的高压熔解曲线的统计矩方法的修改
Modification of the Statistical Moment Method for the High-Pressure Melting Curve by the Inclusion of Thermal Vacancies
论文作者
论文摘要
理论上使用统计矩方法研究了在极端条件下有缺陷晶体的熔融行为。在我们的理论模型中，加热过程通过将它们从平衡位置脱位而导致晶体结构中缺失原子或空位。假定某些原子的配位数被一个单位去除，缺陷取决于温度和外部压力。我们制定分析表达式以直接连接平衡空位浓度，弹性模量和熔化温度。对六种过渡金属进行数值计算，包括Cu，Ag，Au，Mo，TA和W至400 GPA。获得的结果表明，空缺强烈驱动熔融过渡。忽略空缺的形成会导致对熔点的错误预测。我们的数值数据与先前的实验工作之间的良好一致性验证了我们方法的准确性。
Melting behaviors of defective crystals under extreme conditions are theoretically investigated using the statistical moment method. In our theoretical model, heating processes cause missing atoms or vacancies in crystal structures via dislocating them from their equilibrium positions. The coordination number of some atoms is assumed to be removed by one unit and the defect depends on temperature and external pressure. We formulate analytical expressions to directly connect the equilibrium vacancy concentration, the elastic modulus, and the melting temperature. Numerical calculations are carried out for six transition metals including Cu, Ag, Au, Mo, Ta, and W up to 400 GPa. The obtained results show that vacancies strongly drive the melting transition. Ignoring the vacancy formation leads to incorrect predictions of the melting point. The good agreement between our numerical data and prior experimental works validates the accuracy of our approach.
