【摘要】 采用基于密度泛函理论的第一性原理计算方法对BiF₃的结构、弹性和电子性质进行了研究。计算表明,正交的Pnma结构是零压下的最稳定结构。在0⁴5 GPa压力区间内,Pnma结构都是力学稳定的。BiF₃是脆性材料,有较强的弹性各向异性特征。零压下体模量、剪切模量和杨氏模量分别为27.9 GPa,25.7 GPa和58.9 GPa,泊松比为0.15,德拜温度是244 K。电子性质的研究表明,零压下BiF₃的带隙为4.69 eV,随着压强的升高,导带向高能方向移动,价带向低能方向移动。化学键是共价键和离子键的混合。更多还原

【Abstract】 First-principles pseudopotential approach based on density functional theory（ DFT） was used to calculate the structural,elastic and electronic properties of BiF₃. The calculated results indicate that the orthorhombic Pnma structure of BiF₃ is stable at zero pressure. Orthorhombic Pnma structure is more mechanically stable from 0 GPa to 45 GPa. BiF₃ presents better brittle manner and larger elastic anisotropy.The calculated bulk modulus,shear modulus,and the Young’s modulus are 27. 9 GPa,25. 7 GPa,and 58.9 GPa at zero pressure,respectively. The Poisson’s ratio is 0. 15 and the Debye temperature is 244 K. The analysis of electronic properties reveals that the bandgap of BiF₃ is 4. 69 eV at 0 GPa. The conduction band of the structure has a shift tendency toward higher energy,and the valence band has a shift tendency toward lower energy with increasing pressure. BiF₃ is the mixtures of covalent and ionic bonds.更多还原