GaP相变及热力学性质的理论研究
Theoretical study on phase transformation and thermodynamic properties of GaP

利用基于密度泛函理论的第一性原理方法研究了闪锌矿和氯化钠结构的GaP的相变及热力学性质。对两种结构的能量体积曲线做公切线，得到了从闪锌矿到氯化钠结构的相变压力约为26.2GPa, 与实验结果一致。通过准谐德拜模型得到了不同温度下体积和热膨胀系数与压强的关系，以及不同压强下热容与温度的关系。
The phase transformation and thermodynamic properties of GaP with zinc-blende and rocksalt structures are studied using the first-principles method based on density functional theory. The phase transformation pressure from the zinc-blende to rocksalt structure is about 26.2 GPa, which is consistent with the experimental result. Through the quasi-harmonic Debye mode the relationships between the volume, thermal expansion coefficient and the pressure at different temperatures are calculated. And the relationships between the heat capacity and temperature under different pressures are also obtained.