First-principles investigations on elastic and thermodynamic properties of zinc-blende structure BeS

• 来源期刊: 中国物理B（英文版）
• 关键词: density functional theory elastic constants thermodynamic properties Gr(U)eisen parameter BeS PACC: 7115M 6220D 6740K 7470F
• 年，卷（期）: 2008,（4）
• 页码范围: 1377-1382
• 页数: 6页
• 语种: 英文

摘要

In this paper the elastic and thermodynamic properties of the cubic zinc-blende structure BeS at different pressures and temperatures are investigated by using ab initio plane-wave pseudopotential density functional theory method within the generalized gradient approximation (GGA). The calculated results are in excellent agreement with the available experimental data and other theoretical results. It is found that the zinc-blende structure BeS should be unstable above 60GPa. The thermodynamic properties of the zinc-blende structure BeS are predicted by using the quasi-harmonic Debye model. The pressure-volume-temperature (P - V - T) relationship, the variations of the thermal expansion coefficient and the heat capacity Cv with pressure P and temperature T, as well as the Grüneisen parameter-pressure-temperature (γ- P - T) relationship are obtained systematically in the ranges of 0-90GPa and 0-2000K.