Mechanical and thermodynamic properties of ZrO2 under high-pressure phase transition: A first-principles study
Mechanical and thermodynamic properties of ZrO2 under high-pressure phase transition: A first-principles study
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DOI：
10.1016/j.jallcom.2014.08.114
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发表时间：
2015-02
影响因子：
6.2
通讯作者：
Wei Wang;Zuozhong Liang;Xiang-zhen Han;Jianfeng Chen;Chunyu Xue;Hong Zhao
中科院分区：
文献类型：
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作者：
Wei Wang;Zuozhong Liang;Xiang-zhen Han;Jianfeng Chen;Chunyu Xue;Hong Zhao
首次用密度泛函理论方法系统地研究了二阶相变过程(P21/c→Pbca→Pnma)中ZrO2的相稳定性、力学和热力学性质与压力的关系。由吉布斯自由能计算发现，P21/c→Pbca→Pnma相变分别发生在9.09 Gpa和12.68 Gpa左右。此外，还计算了ZrO2的基态性质，如晶格参数和弹性常数，与前人的工作符合得很好。理论计算表明，当压力从0 Gpa增加到20 Gpa时，ZrO2的弹性常数(Cij)、体积弹性系数(B)、剪切弹性系数(G)、杨氏弹性系数(E)、泊松比(ν)、弹性各向异性(AU)、脆/韧性特性(B/G)、硬度(HV)和德拜温度(Θ)几乎都经历了不同程度的变化。此外，在此过程中，氧化锆的相关相在相应的压力范围内保持了热力学和机械稳定性。综上所述，本研究对氧化锆的力学和热力学性质进行了定量的理论预测，为今后的理论计算和实验结果提供了参考数据。
The pressure-dependence behaviors of phase stability, mechanical and thermodynamic properties of ZrO2in the second-order phase transition procedure (P21/c→Pbca→Pnma) were systematically investigated for the first time by using density functional theory (DFT) calculations. We found that the phase transformation,P21/c→Pbca→Pnma, occurs at around 9.09 GPa and 12.68 GPa from the Gibbs free energy calculations, respectively. Furthermore, the ground state properties, such as the lattice parameter and elastic constants of ZrO2were also calculated which yield good agreement with previous work available. From the theoretical calculations, the elastic constants (Cij), bulk modulus (B), shear modulus (G), Young’s modulus (E), Poisson’s ratio (ν), elastic anisotropy (AU), brittle/ductile characteristic (B/G), hardness (HV) and Debye temperature (Θ) of ZrO2almost all experience different degrees of changes with the increasing pressure from 0 GPa to 20 GPa. Additionally, the related phases of ZrO2keep thermodynamic and mechanical stability in the corresponding range of pressure during the procedure. Overall, this study presents insight on the quantitative theoretical prediction of mechanical and thermodynamic properties of ZrO2and may provide references data for the future theoretical calculations and experimental results.