采用基于密度泛函理论的第一性原理计算方法研究了钙钛矿结构的BaHfO3和SrHfO3的基态性质,包括优化后的晶格常数、弹性常数、体弹性模量、剪切模量、态密度、能带结构和电荷密度.计算结果表明BaHfO3和SrHfO3具有比较大的体弹性模量,它们都是间接带隙的半导体材料,Ba或Sr原子与HfO3基团之间形成的化学键主要是离子键,而Hf原子与O原子之间形成的主要是共价键.
Perovskite-type BaHfO3 and SrHfO3 are studied using the first principle density functional method. The lattice parameters, elastic constants, bulk and shear moduli, density of states, band structures and charge densities of BaHfO3 and SrHfO3 are calculated after structural relaxation. The calculation results show that both BaHfO3 and SrHfO3 are indirect semiconductors with relatively higher bulk moduli. In the unit cell, the ionic bond is formed between Sr (Ba) atom and HfO3, while the covalent bond is formed between Hf atom and O atom.