四方晶相SrHfO3弹性性质、电子结构和光学性质的第一性原理计算 First-Principles Calculations of Elastic, Electronic and Optical Properties of Tetragonal SrHfO 3 Crystal

本文采用基于密度泛函理论(DFT)框架下广义梯度近似平面波超软赝势法，对四方晶相SrHfO3的晶体结构、弹性性质、电子结构和光学性质进行了计算。计算得到的晶格常数与实验值相符；计算结果表明四方SrHfO3的晶体结构是稳定的，属于直接带隙钙钛矿型复合氧化物，最小带隙为3.39 eV；计算并分析了四方SrHfO3在(100)和(001)方向上光学线性响应函数随光子能量的变化关系，包括复介电函数、复折射率、反射光谱、吸收光谱、损失函数和光电导谱；计算得到其静态介电常数在(100)和(001)方向上分别为3.69和3.73，折射率分别为1.92和1.93；计算结果表明了四方SrHfO3在(100)和(001)方向上具有光学各向异性，这为四方SrHfO3的应用提供了理论依据。 Structural parameters, elastic properties, electronic structure and optical properties of t-SrHfO3 have been investigated using the plane waves ultrasoft pseudopotential technique based on the density func-tional theory (DFT). The calculated lattice parameters are in good agreement with the experimental data and the calculated elastic constants show that t-SrHfO3 is elastically stable. The calculated results of electronic structure show t-SrHfO3 belongs to direct band gap perovskite composite oxides with the band gap of 3.39 eV. The optical linear response functions of t-SrHfO3 as a function of photon energy were obtained including the complex dielectric function, complex of refractive, reflectivity, absorption coefficients, loss function and complex conductivity function from (100) and (001) directions. The static dielectric constants are 3.69 and 3.73, the refractivity indices are 1.92 and 1.93 from (100) and (001) directions, respectively. The calculated optical properties of t-SrHfO3 show an optical anisotropy in the components of polarization directions (100) and (001), which offer a theoretical basis for the applications of t-SrHfO3.