纤维锌矿结构GaN热力学性质的第一性原理计算(英文)

First-principles calculations of thermodynamic properties of GaN with wurtzite structure

利用平面波赝势密度泛函方法,结合广义梯度近似,对纤维锌矿GaN的结构和热力学性质进行了计算,发现纤维锌矿结构GaN的最稳定的结构对应的结构参数为:u=0.3769,c/a=1.628,a=3.204,andc=5.216,所得结果与实验和其他理论的结果相符.通过准谐德拜模型,我们还成功得到了w-GaN的相对体积、热膨胀系数、热容和德拜温度等热力学量.

The structural and thermodynamic properties of hexagonal wurtzite structure GaN （w-GaN） are calculated by using ab initio plane-wave pseudopotential density functional theory （DFT） within the generalized gradient approximation （GGA）. It is found that the most stable structure of the w-GaN corresponds to u =0.3769, c/a = 1. 628, a = 3. 204 A, and c = 5. 216 A. Our results are consistent with the experimental data and other theoretical results. Through the quasi-harmonic Debey model, the normalized primitive cell volume, thermal expansion coefficient, heat capacity and Debye temperature are successfullv obtained.