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采用基于密度泛函理论的平面波超软赝势方法研究了正交相SrHfO3和以Si替换Hf方式形成的掺杂态SrHfO3的形成能,几何结构,电子结构和光学性质。负的形成能表明在由单元素形成Si掺杂态的SrHfO3的反应中,Si占居Hf位置与Sr位置两种情况在能量上是有利的,并且Si原子更加倾向于占居Hf位置。纯的SrHfO3计算得到的晶格常数与文献报道的实验值和理论值是一致的,而Si占居Hf位置后会导致SrHfO3的晶格常数减小。能带结构显示在掺入Si原子后会使带隙变小。布居分析与电荷密度图一致,说明在Hf位置掺入Si后掺杂位置附近的Hf-O键以共价键为主,Sr-O键以离子键为主。最后,对Si掺杂后SrHfO3在(100)方向上的介电常数、反射率、吸收系数、折射率进行了计算与分析。
The formation energies, geometrical structures, electronic structures and optical properties of SrHfO3 doped with orthorhombic SrHfO3 and Hf replaced with Si were studied by plane wave super soft pseudopotential method based on density functional theory. The negative formation shows that in the reaction of forming Sr-doped SrHfO3 from a single element, Si is energetically favorable for both Hf and Sr sites, and Si atoms are more likely to occupy Hf sites. The calculated lattice constants of pure SrHfO3 are in agreement with the experimental and theoretical values reported in the literature, while the Si occupies the Hf position and leads to the decrease of the lattice constant of SrHfO3. The band structure shows that the band gap becomes smaller when Si atoms are doped. The population analysis is in agreement with the charge density diagram, indicating that the Hf-O bond near the doping site at Hf site is dominated by the covalent bond, and the Sr-O bond is dominated by the ionic bond. Finally, the dielectric constant, reflectivity, absorption coefficient and refractive index of SrHfO3 in the (100) direction after Si doping were calculated and analyzed.