Low-Temperature Structure and Dynamics in Cu2Se
Low-Temperature Structure and Dynamics in Cu2Se
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DOI：
10.1021/acs.jpcc.5b06079
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发表时间：
2015-08
影响因子：
3.7
通讯作者：
A. Sirusi;S. Ballikaya;C. Uher;J. H. Ross
中科院分区：
文献类型：
--
作者：
A. Sirusi;S. Ballikaya;C. Uher;J. H. Ross
我们报告63铜和65铜NMR Cu 2Se，超离子导体的兴趣热电和其他应用。结果表明，最初出现的离子跳跃在一个狭窄的温度范围内高于100 K，符合最近观察到的低温相变。在室温及更高温度下，这转变为快速的Cu离子跳跃和在α-β结构转变上方和下方的单个运动窄化线。与高温结构相比，低温α′相表现出相当大的金属位移。原生载流子密度的变化很大，在与Cu空位相关的位置处显着增强，表明杂质带对低温电子输运的强烈影响。
We report 63Cu and 65Cu NMR on Cu2Se, a superionic conductor of interest for thermoelectric and other applications. Results demonstrate an initial appearance of ionic hopping in a narrow temperature range above 100 K, coinciding with the recently observed low-temperature phase transition. At room temperature and above, this goes over to rapid Cu-ion hopping and a single motionally narrowed line both above and below the α–β structural transition. The low-temperature α′ phase exhibits a sizable metallic shift, in contrast to the high-temperature structures. The large variation in native carrier density, significantly enhanced at positions associated with Cu vacancies, indicates the strong influence of an impurity band on low-temperature electronic transport.