高压下金属铌熔化曲线的分子动力学模拟

铌作为一种高熔点的金属，广泛应用于制作合金材料. 铌的高温高压熔化曲线对于铌基合金的实际应用具有重要影响，但目前还未被成功研究. 本文中，我们采用铌目前已有的嵌入原子相互作用势函数（EAM），通过经典的分子动力学方法，模拟了铌的熔化曲线. 两相法和改进Z方法的熔化曲线几乎完全一致，与Z方法的结果稍有差异. 我们也比较了尺寸效应对铌熔化曲线的影响. 我们认为，铌的现有的势函数描述其高压特性时不再适合，后续需要构建精确的温度和压强依赖的相互作用势函数来研究铌的高压特性.

Molecular dynamics simulations of melting curves of metal Nb under high pressure

As a metal with high melting point, niobium is widely used in making alloy materials. The melting curve of niobium at high temperature and high pressure has an important influence on the practical application of niobium alloys, but it has not been studied successfully. In this paper, the melting curve of niobium is simulated by classical molecular dynamics method using the existing embedded atom interaction potential function (EAM) of niobium. The melting curves of the two phase method and the modified Z method are almost identical, but the results are slightly different from those of the Z method. We also compare the effect of the size effect on the melting curves. We believe that the existing potential function of niobium is no longer suitable to describe its high-pressure characteristics, and we need to construct an accurate temperature and pressure dependent interaction potential function to study the high-pressure characteristics of niobium in the future.