TY - JOUR
T1 - Metallic versus insulating behavior in the A -site ordered perovskite oxides A Cu3 Co4 O12 (A=Ca and Y) controlled by Mott and Zhang-Rice physics
AU - Mizokawa, Takashi
AU - Morita, Yosuke
AU - Sudayama, Takaaki
AU - Takubo, Kou
AU - Yamada, Ikuya
AU - Azuma, Masaki
AU - Takano, Mikio
AU - Shimakawa, Yuichi
PY - 2009/9/8
Y1 - 2009/9/8
N2 - We report on a photoemssion study of A -site ordered perovskite oxides A Cu3 Co4 O12 (A=Ca and Y) which are metallic for A=Ca and insulating for A=Y. If the Cu valence is +2 as stabilized by the square planar coordination, the Co valence for A=Ca is formally +4 and the system could be a Mott insulator while that for A=Y should be +3.75 and the system is a doped Mott insulator. The photoemission study reveals that the Cu valence for A=Ca and Y is formally +3 with the d9 L configuration (L: an O2p hole) which corresponds to the Zhang-Rice singlet state. In addition, it is found that the Co valence for A=Y is formally +3 with the low-spin d6 configuration consistent with its insulating behavior.
AB - We report on a photoemssion study of A -site ordered perovskite oxides A Cu3 Co4 O12 (A=Ca and Y) which are metallic for A=Ca and insulating for A=Y. If the Cu valence is +2 as stabilized by the square planar coordination, the Co valence for A=Ca is formally +4 and the system could be a Mott insulator while that for A=Y should be +3.75 and the system is a doped Mott insulator. The photoemission study reveals that the Cu valence for A=Ca and Y is formally +3 with the d9 L configuration (L: an O2p hole) which corresponds to the Zhang-Rice singlet state. In addition, it is found that the Co valence for A=Y is formally +3 with the low-spin d6 configuration consistent with its insulating behavior.
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U2 - 10.1103/PhysRevB.80.125105
DO - 10.1103/PhysRevB.80.125105
M3 - Article
AN - SCOPUS:70350648388
VL - 80
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 12
M1 - 125105
ER -