不同氧化锆相的稳定性及电子结构的第一性原理研究

通过密度泛函理论计算了不同氧化锆相的晶体结构参数，在所有晶相模型结构优化的基础上，分析了在一般温度和压力下不同晶相稳定程度不同的原因。使用3种不同的泛函计算了不同晶相的电子能带结构和态密度电荷差分密度，发现在氧化锆高温稳定相体系中，由于强关联电子的相互作用增强，传统密度泛函理论的广义梯度近似平面波超软赝势泛函及其修正的Hubbard U方法都会严重低估能带带隙，因此所得各层能带位置不准确，而使用B3LYP杂化泛函计算的结果则可以很好地与已有实验结果相吻合。结合杂化泛函计算出的态密度和差分密度数据，在理论上从电子间相互作用的角度解释了氧化锆不同晶相的稳定性、导电性及光吸收性能。

First-principles study of the stability and electronic structure of different zirconia phases

The crystal structure parameters of different zirconia phases have been calculated using density functional theory (DFT). On the basis of all the model structure optimization, the reasons for the different stabilities of different crystal phases at a general temperature and pressure are analyzed. The electronic band structures and state density charge differential densities of different crystal phases have been calculated using three different functionals. It is found that in the zirconia high temperature stable phase system, the interaction between strongly correlated electrons in zirconia is enhanced. The generalized gradient approximation plane wave ultra-soft pseudopotential functional of traditional density functional theory and its modified Hubbard U method seriously underestimate the energy band gap, so the band position of each layer is not accurate, but the calculated results using the B3LYP hybrid functional are in good agreement with the existing experimental results. By combining with the density of states and differential density data calculated by B3LYP hybrid functional, the stability, electrical conductivity and optical absorption properties of different crystal phases of zirconia have been explained theoretically from the aspect of electron-to-electron interaction.