Density functional study of the phase diagram and thermodynamic properties of Zr
Density functional study of the phase diagram and thermodynamic properties of Zr
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Zr相图和热力学性质的密度泛函研究
DOI：
10.1016/j.commatsci.2010.10.017
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Cai, Ling-Cang
中科院分区：
文献类型：
--
作者：
Hu, Cui-E.;Zeng, Zhao-Yi;Cai, Ling-Cang
我们用第一性原理计算研究了Zr的结构、声子色散、相变和热力学。在零压下，α-Zr在0.98 Gpa时转变为omega-Zr，然后在31.6 Gpa时转变为β-Zr。对于α-Zr，轴比c/a随压力的增加而增大，而对于omega-Zr，轴比c/a在压缩下几乎不变。在准谐德拜模型下，得到了Zr的全相图。在1130K发生了从α-Zr到β-Zr的零压相变，300K时从α-Zr到Co-Zr的相变压力为2.10 GPa.预测的三相点为6.35 GPa910K，与实验值接近.成功地预测了在较宽的压力和温度范围内的热物性，包括熵、等温线、等压线和热压。(C)2010爱思唯尔B.V.保留所有权利。
We have investigated the structures, phonon dispersions, phase transitions and thermodynamics of Zr from first-principles calculations. At zero temperature, alpha-Zr transforms to omega-Zr at 0.98 GPa and then to beta-Zr at 31.6 GPa. The axial ratio c/a increases with increasing pressure for alpha-Zr, but it is nearly invariant under compression for omega-Zr. Within the quasi-harmonic Debye model, the full phase diagram of Zr was obtained. The zero pressure phase transition from alpha-Zr to beta-Zr occurs at 1130 K. The transition pressure from alpha-Zr to co-Zr at 300 K is 2.10 GPa and the predicted triple point is at 6.35 GPa, 910K, which is close to the experimental data. The thermal properties including the entropy, isotherm, isobar and thermal pressure in a wide range of pressure and temperature were predicted successfully. (C) 2010 Elsevier B.V. All rights reserved.