Structure and phase stability of alloys based on systematic first principles thermodynamics calculations

统计热力学在现代材料科学中起着重要的作用。化合物的自由能是讨论相稳定性不可缺少的因素。一般来说，许多现象有助于自由能的温度依赖性。在多组分系统中，原子构型对自由能的一个重要贡献。通过密度泛函理论计算和簇展开法对构型效应进行了估计。因此，提出了基于DFT计算和CE方法的构型性质计算方法。我们建立了伪二元MgO-ZnO和MgO-NiO体系的基态结构和相图。此外，通过第一性原理分子动力学计算，估计了在有限温度下的平均结构。

Statistical thermodynamics plays a crucial role in modern materials science. The free energy of compounds is indispensable for discussing the phase stability. In general, a number of phenomena contribute to the temperature dependence of the free energy. In multicomponent systems, an important contribution to the free energy arises from the atomic configuration. The configurational effects have been estimated by density functional theory calculations and the cluster expansion method. Therefore, methodologies for computing the configurational properties, based on DFT calculations and the CE method, are proposed. We have constructed ground state structures and phase diagrams for a pseudobinary MgO-ZnO and MgO-NiO systems. In addition, the average structure at a finite temperature has been estimated by carrying out first-principles molecular dynamics calculations.