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采用第一性原理研究了压力对正交相Sr Hf O3电子结构的影响。正交相Sr Hf O3在零压力时的结构参数与已有的实验值和理论计算值一致。当施加的压力小于20 GPa时,正交相Sr Hf O3的最小间接带隙在Z-Γ之间。当施加的压力大于20 GPa时,正交相Sr Hf O3的最小间接带隙在S-Γ之间。随着压力的增加,正交相Sr Hf O3的态密度向低能量方向移动。电荷密度分析表明,Hf-O之间主要以共价键结合,Sr-O之间主要以离子键结合。随着压力的增加,Hf-O共价键和Sr-O离子键增强,而Sr-Hf O3之间的离子交互作用减弱。
The effect of pressure on the electronic structure of Sr Hf O3 in the orthorhombic phase was investigated using first principles. The structural parameters of the orthorhombic Sr Hf O3 at zero pressure are consistent with the existing experimental and theoretical calculations. The minimum indirect bandgap of the orthorhombic Sr Hf O3 is between Z and Γ when the applied pressure is less than 20 GPa. When the applied pressure is greater than 20 GPa, the minimum indirect bandgap of the orthorhombic Sr Hf O3 lies between S-Γ. With the increase of pressure, the density of the orthorhombic Sr Hf O3 shifts to the low energy. Charge density analysis showed that Hf-O mainly covalently bonded, Sr-O mainly by ionic bond. With the increase of pressure, Hf-O covalent bond and Sr-O ionic bond increased, while the ionic interaction between Sr-Hf O3 weakened.