Ab initio calculations of the thermodynamics and phase diagram of zirconium
Ab initio calculations of the thermodynamics and phase diagram of zirconium
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锆热力学和相图的从头算
DOI：
10.1103/physrevb.78.134101
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发表时间：
2008-10
影响因子：
3.7
通讯作者：
Wu, Qiang
中科院分区：
文献类型：
--
作者：
Chen, Xiang-Rong;Alfe, Dario;Cai, Ling-Cang;Hao, Yan-Jun;Zhang, Lin;Wu, Qiang
利用有限温度密度泛函理论和准调和晶格动力学计算了Zr的六方密排（hcp）和欧米茄（omega）晶体结构的吉布斯自由能和准调和声子。hcp声子色散与实验相符；声子色散还没有被测量。从自由能出发，预测了zr的体积热膨胀系数。计算得到的α - zr的体积热膨胀系数与实验数据吻合较好。我们的计算结果发现，在零温度下，能量最低的相不是欧米茄，而是hcp相。这一结论与Schnell and Albers的结果一致，但与Ahuja和Jona and Marcus的结果不一致。预测的α -> - ω相界与已有实验结果吻合较好；然而，其他理论结果与高温下的实验结果相去甚远。
The finite-temperature density-functional theory and quasiharmonic lattice dynamics are used to calculate the Gibbs free energy and quasiharmonic phonons of the hexagonal-close-packed (hcp) and omega (omega) crystal structures for Zr. The hcp phonon dispersions agree with experiment; the omega phonon dispersions have not been measured yet. From the free energy, the volume thermal expansion coefficients of alpha-Zr are predicted. The calculated volume thermal expansion coefficients for alpha-Zr are in good agreement with the experiment data at T>100 K. Our calculated results found that at zero-temperature the lowest-energy phase is not the omega but the hcp phase. This conclusion is in accordance with the result of Schnell and Albers, but in disagreement with those of Ahuja and Jona and Marcus. The predicted phase boundary of alpha ->omega is in good agreement with the available experiment; however, other theoretical results are far from the experiment at high temperatures.
DOI：
10.2172/4010212
发表时间：
1991-05
期刊：
--
影响因子：
--
作者：
D. Young
通讯作者：
D. Young