High-pressure phase transitions in rare earth metal thulium to 195 GPa
High-pressure phase transitions in rare earth metal thulium to 195 GPa
复制标题
稀土金属铥高压相变至 195 GPa
DOI：
10.1088/0953-8984/23/15/155701
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Y. Vohra
中科院分区：
文献类型：
--
作者：
J. Montgomery;G. Samudrala;G. Tsoi;Y. Vohra
我们在金刚石砧室中对重稀土金属铥 (Tm) 进行了图像板 X 射线衍射研究，室温下压力为 195 GPa，体积压缩 V/Vo = 0.38。在 Tm 低于 70 GPa 时观察到稀土晶体结构序列，扭曲的面心立方，但纯面心立方相除外。我们研究的重点是 70 至 195 GPa 压力范围内的超高压相变和晶体结构的 Rietveld 细化。六方 hR-24 相描述了 70 至 124 GPa 之间的扭曲 fcc 相。在 124 ± 4 GPa 以上，观察到从 hR 24 相到单斜 C 2/m 相的结构转变，体积变化为 − 1.5%。状态方程数据显示在 124 GPa 的相变以上出现快速硬化，表明 f 电子参与键合。我们将 Tm 与其他重稀土和重锕系金属在极端压力条件下的行为进行了比较。
We have performed image plate x-ray diffraction studies on a heavy rare earth metal, thulium (Tm), in a diamond anvil cell to a pressure of 195 GPa and volume compression V/Vo = 0.38 at room temperature. The rare earth crystal structure sequence, distorted fcc, is observed in Tm below 70 GPa with the exception of a pure fcc phase. The focus of our study is on the ultrahigh-pressure phase transition and Rietveld refinement of crystal structures in the pressure range between 70 and 195 GPa. The hexagonal hR- 24 phase is seen to describe the distorted fcc phase between 70 and 124 GPa. Above 124 ± 4 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of − 1.5%. The equation of state data shows rapid stiffening above the phase transition at 124 GPa and is indicative of participation of f-electrons in bonding. We compare the behavior of Tm to other heavy rare-earths and heavy actinide metals under extreme conditions of pressure.