Simultaneous electrical and X-ray diffraction studies on neodymium metal to 152 GPa
Simultaneous electrical and X-ray diffraction studies on neodymium metal to 152 GPa
复制标题
对 152 GPa 的金属钕进行同步电学和 X 射线衍射研究
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Weir
中科院分区：
文献类型：
--
作者：
N. Velisavljevic;Y. Vohra;S. Weir
使用设计的金刚石砧和角色散X射线衍射技术在同步辐射源，我们进行了同步的电子和结构的研究，钕金属在152 GPa的金刚石砧细胞。四探针电阻测量显示，与4f-壳层电子的离域相关的电阻率降低了38%，从100 GPa开始到152 GPa的最终压力。电阻率的持续下降与在该压力范围内观察到的逐渐向α-U结构的相变相一致。α-U结构的（111）衍射峰在100 GPa处出现，随着压力的增加，衍射峰强度逐渐增强，直到152 GPa。这种强度的增加归因于α-U相体积分数的增加和结构y参数从118 GPa时的0.07增加到152 GPa时的0.095。与铈和镨中的突然压力诱导f电子跃迁相反，钕中α-U结构和电阻率的连续演化证实了该元素4f离域过程的渐进性质。
Using designer diamond anvils and angle dispersive X-ray diffraction technique at a synchrotron source, we have performed simultaneous electrical and structural studies on neodymium metal to 152 GPa in a diamond anvil cell. Four-probe electrical resistance measurement shows a 38% decrease in the electrical resistivity, associated with the delocalization of the 4f-shell electrons, starting at 100 GPa up to a final pressure of 152 GPa. The continuous decrease in electrical resistivity is consistent with the observation of a gradual phase transition to α-U structure in this pressure range. The (1 1 1) diffraction peak of α-U structure first appears at 100 GPa and increases in intensity with increasing pressure to 152 GPa. This increase in intensity is attributed to an increasing volume fraction of α-U phase and an increase in structural y-parameter from 0.07 at 118 GPa to 0.095 at 152 GPa. In contrast to the abrupt pressure-induced f-electron transition seen in cerium and praseodymium, the continuous evolution of α-U structure and electrical resistivity in neodymium confirms the gradual nature of 4f delocalization process in this element.