Cu -edge X-ray absorption fine structure study of -type CuO ( = Rare Earth); Toward unified understanding of electronic state of -type cuprate

Chen, Y.*; Asano, Shun*; Wang, T.*; Xie, P.*; Kitayama, Shinnosuke*; Ishii, Kenji*; Matsumura, Daiju   ; Tsuji, Takuya  ; Taniguchi, Takanori*; Fujita, Masaki*

To investigate the variation of the electronic state of -type cuprate due to annealing, we performed Cu -edge X-ray absorption fine structure measurements on PrCuO (PCO) and PrLaCuO (PLCO). The induced electrons due to annealing () in PCO and PLCO were approximately 2, consistent with a model of electron doping to Mott insulator. Here, and represent the amount of excess oxygen from the stoichiometric composition in the as-sintered compound and that of oxygen loss due to annealing, respectively. Furthermore, the energy of the Einstein oscillator () for the Cu-O bond was evaluated by extended X-ray absorption fine structure analysis. (O denotes the in-plane oxygen.) We found a small annealing effect on for both PCO and PLCO.