Ce substitution and reduction annealing effects on electronic states in Pr
Ce
CuO
studied by Cu
-edge X-ray absorption spectroscopy
Pr
Ce
CuO
におけるCe置換と還元アニールがもたらす電子状態変化の銅
吸収端X線吸収分光観測
浅野 駿*; 石井 賢司*; 松村 大樹
; 辻 卓也
; 伊奈 稔哲*; 鈴木 謙介*; 藤田 全基*
Asano, Shun*; Ishii, Kenji*; Matsumura, Daiju; Tsuji, Takuya; Ina, Toshiaki*; Suzuki, Kensuke*; Fujita, Masaki*
We investigated the Ce substitution and reduction annealing effects on the electronic states at copper sites by Cu
-edge X-ray absorption near-edge structure measurements in Pr
Ce
CuO
(PCCO) with varying
and
(amount of oxygen loss during annealing). Absorption near-edge spectra were modified by Ce substitution and reduction annealing similarly with increasing
and
. Considering electron doping by Ce substitution, this similarity indicates an increase in electron number at the copper sites due to annealing (
). Furthermore, quantitative analyses of the spectra clarified that the number of Cu
sites, corresponding to the induced electron number by Ce substitution increases linearly with
in the as-sintered PCCO, whereas
is not exactly equal to 2
. For each
-fixed sample,
tends to exceed 2
with increasing
, suggesting the emergence of two types of carrier due to annealing.