高压下钡的硫化物的结构相变和光学性质研究(英文)

利用基于密度泛函的第一性原理,计算了高压下钡的硫化物(BaS、BaSe和BaTe)的结构相变和光学性质。计算结果表明,这些化合物的压致结构相变是从NaCl型结构转变为CsCl型结构;对于结构转变压力和金属化转变压力,BaS为8.57 GPa和45.4 GPa,BaSe为7.44 GPa和36.5 GPa,BaTe则分别为5.67 GPa和16.7 GPa。光学性质计算结果显示:随着压力的增加,静态介电常数ε0不断增加,介电常数虚部ε2的峰值向高能方向移动(蓝移)。

Structural Stabilities and Optical Properties of BaX (X=S,Se and Te)under High Pressure

An investigation on the structural stabilities and optical properties of BaX (X=S,Se and Te) under high pressure was conducted using first-principles calculations based on density functional theory. The results show that the sequence of the pressure-induced phase transition of these compounds is from the NaCl-type (B1) to the CsCl-type (B2) structure. The structural transition pressure and the metallization pressure are 8. 57 and 45. 4 GPa for BaS,7. 44 and 36. 5 GPa for BaSe,5. 67 and 16. 7 GPa for BaTe,respectively. The calculation of the optical properties showed that almost all peaks of the imaginary part of dielectric constant (ε2) in the B1 and B2 structures shift towards high-energy region with increasing pressure (blue shift),and the static dielectric constant increases as the pressure increases.