Phase transitions and equation of state of zirconium under high pressure
Phase transitions and equation of state of zirconium under high pressure
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DOI：
10.1103/physrevb.102.184105
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发表时间：
2020-11-10
影响因子：
3.7
通讯作者：
Dewaele, Agnes
中科院分区：
文献类型：
--
作者：
Anzellini, Simone;Bottin, Francois;Dewaele, Agnes
在300K、高达142 Gpa的准静水压条件下，在金刚石顶压室中进行的X射线衍射测量表明，α-Zr-&Gt；(17 Gpa)omega-Zr-&Gt；(35 Gpa)β-Zr相变序列。用从头算方法对体心立方β-Zr在300~1000K和0~100 Gpa范围内进行了分子动力学计算，得到了与实验非常一致的状态方程。通过数值加热猝灭实验验证了β-Zr在压力下的稳定性，并对其热振动的非谐性进行了评价。在25~100 Gpa范围内没有发现软模引起的动力学不稳定性，这与实验发现的β-Zr较宽的稳定范围是一致的。
X-ray diffraction measurements performed in a diamond anvil cell under quasihydrostatic conditions up to 142 GPa at 300 K evidence an alpha-Zr -> (17 GPa) omega-Zr -> (35 GPa) beta-Zr phase transitions sequence. Ab initio molecular dynamics calculations performed on the body-centered cubic beta-Zr at 300 and 1000 K and between 0 and 100 GPa produced an equation of state in excellent agreement with the experiments. The stability of beta-Zr under pressure has been verified by numerical heating-quenching experiments, and the anharmonicity of the thermal vibrations has been evaluated. No dynamical instability due to a soft mode is evidenced between 25 and 100 GPa, in line with the experimental finding of a wide stability range for beta-Zr.