Ab initio calculation of the lattice dynamics and phase diagram of boron nitride
Ab initio calculation of the lattice dynamics and phase diagram of boron nitride
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DOI：
10.1103/physrevb.59.8551
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发表时间：
1999-04-01
影响因子：
3.7
通讯作者：
Hafner, J
中科院分区：
文献类型：
--
作者：
Kern, G;Kresse, G;Hafner, J
我们提出了一个详细的晶格动力学和立方锌（c-BN）和六方（h-BN）氮化硼的相稳定性的研究。用第一性原理力常数法计算了不同密度下的声子色散关系。计算的本征频率和声子Gruneisen参数与实验结果符合得很好。从电子和振动能量作为体积的函数，我们计算的相位（P，T）图氮化硼在准谐波近似。Ar低温下c-BN是稳定的变质剂，c-BN/h-BN共存线与温度轴相交于1440 K。在实验中，该温度在1200和1800 K之间。非谐修正改善了高温高压下计算与实验的一致性。[S0163-1829（99）06513-3]。
We present a detailed study of the lattice dynamics and of the phase stability of cubic zincblende (c-BN) and hexagonal (h-BN) boron nitrides. The phonon-dispersion relations at different densities are calculated using a first-principles force-constant method. The calculated eigenfrequencies and phonon Gruneisen parameters are in good agreement with experimental findings. From the electronic and vibrational energies as a function of volume we calculate the phase (p,T) diagram of boron nitride in a quasiharmonic approximation. Ar low temperature c-BN is the stable modification; the c-BN/h-BN coexistence line intersects the temperature axis at 1440 K. in experiments this temperature lies between 1200 and 1800 K. Anharmonic corrections improve the agreement between the calculation and experiment for high pressure and temperature. [S0163-1829(99)06513-3].