Reduction and oxidation annealing effects on Cu K-edge XAFS for electron-doped cuprate superconductors
Reduction and oxidation annealing effects on Cu K-edge XAFS for electron-doped cuprate superconductors
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DOI：
10.1088/1742-6596/969/1/012051
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
S. Asano;K. Suzuki;D. Matsumura;K. Ishii;T. Ina;M. Fujita
中科院分区：
文献类型：
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作者：
S. Asano;K. Suzuki;D. Matsumura;K. Ishii;T. Ina;M. Fujita
利用Cu的K边X射线吸收谱研究了还原和氧化退火对Pr_（2-x）CexCuO_4和Nd_（2-x）CexCuO_4（x = 0和x = 0.15）中Cu位周围电子态的影响. Cu K近边光谱的改变，通过还原退火的方式类似的情况下的Ce替代x = 0和x = 0.15。这意味着在铜位点的电子密度的增加，表明在还原退火中的电子掺杂的方面。这种还原退火对近边光谱的影响被额外的氧化退火所逆转。铜位点周围的电子密度的量通过还原和氧化退火可逆地改变，对应于从绝缘到超导的物理性质的可逆变化。
Reduction and oxidation annealing effects on the electronic states around the copper sites for Pr2-xCexCuO4 and Nd2-xCexCuO4 with x = 0 and x = 0.15 were investigated by Cu K-edge x-ray absorption measurements. Cu K near-edge spectra were changed by the reduction annealing in a manner similar to the case of Ce substitution for both x = 0 and x = 0.15. This means an increase of electron density at the copper sites, indicating the aspect of electron doping in the reduction annealing. This reduction annealing effect on the near-edge spectra are reverted by the additional oxidation annealing. The amount of electron density around the copper sites is varied by the reduction and oxidation annealing, reversibly, corresponding to the reversible variation of the physical property from insulating to superconductivity.