Reduction and oxidation annealing effects on the electronic states around the copper sites for Pr2-xCe x CuO4 and Nd2-xCe x CuO4 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.
|Journal||Journal of Physics: Conference Series|
|Publication status||Published - 2018 Apr 19|
|Event||28th International Conference on Low Temperature Physics, LT 2018 - Gothenburg, Sweden|
Duration: 2017 Aug 9 → 2017 Aug 16
ASJC Scopus subject areas
- Physics and Astronomy(all)