TY - JOUR
T1 - Local structure and valence states in PbBaSrY1-xCaxCu3O7+δ and Pb2Sr2Y1-xCaxCu3O8+δ
AU - Yamaguchi, H.
AU - Oyanagi, H.
AU - Tokiwa, A.
AU - Syono, Y.
PY - 1991/12/1
Y1 - 1991/12/1
N2 - X-ray absorption fine structure on the Cu K and the Pb L3-edges of PbBaSrY1-xCaxCu3O7+δ and Pb2Sr2Y1-xCaxCu3O8+δ systems has been measured. In the oxygen-deficient phase with δ=0 of these systems, the Cu K-near-edge spectra evidence the existence of Cu1+ comprised in OCuO linear chains. The Cu K-edge position shifts to higher energy retaining the Cu1+ feature by substitution of Y3+ with Ca2+ in the oxygen-deficient phase, indicating that holes are supplied to the CuO2 basal planes of the pyramids. The Pb valence is found to be mixed states of 2+ and 4+ in the oxygen-rich phases with δ>1. The average Pb valence is estimated as 3.3+ and 3.04+ in PbBaSrYCu3O8.4 and Pb2Sr2YCu3O9.5, respectively.
AB - X-ray absorption fine structure on the Cu K and the Pb L3-edges of PbBaSrY1-xCaxCu3O7+δ and Pb2Sr2Y1-xCaxCu3O8+δ systems has been measured. In the oxygen-deficient phase with δ=0 of these systems, the Cu K-near-edge spectra evidence the existence of Cu1+ comprised in OCuO linear chains. The Cu K-edge position shifts to higher energy retaining the Cu1+ feature by substitution of Y3+ with Ca2+ in the oxygen-deficient phase, indicating that holes are supplied to the CuO2 basal planes of the pyramids. The Pb valence is found to be mixed states of 2+ and 4+ in the oxygen-rich phases with δ>1. The average Pb valence is estimated as 3.3+ and 3.04+ in PbBaSrYCu3O8.4 and Pb2Sr2YCu3O9.5, respectively.
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U2 - 10.1016/0921-4534(91)91650-S
DO - 10.1016/0921-4534(91)91650-S
M3 - Article
AN - SCOPUS:0004872516
VL - 185-189
SP - 853
EP - 854
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - PART 2
ER -