TY - JOUR
T1 - Crystal structure and superconductivity in La1.95Bi0.05CuO4+δ oxidized by a KMnO4 aqueous solution
AU - Kato, Masatsune
AU - Chizawa, Hiroshi
AU - Ono, Yasuhiro
AU - Koike, Yoji
N1 - Funding Information:
We thank Y. Saito and T. Noji for their continuous encouragement in the course of this study. One of the authors (MK) was supported by a Grant-in-Aid for Scientific Research given by the Ministry of Education, Science and Culture, Japan.
PY - 1996/1/10
Y1 - 1996/1/10
N2 - We have obtained La1.95Bi0.05CuO4+δ with various values of δ by the KMnO4 oxidation method. The largest value of δ≈0.136 is about twice as large as that obtained by annealing under high pressures of oxygen, δ≈0.056. A structural phase transition from the orthorhombic to the tetragonal phase with the increase of δ is observed at δ=0.035-0.04. For δ≳0.08, another orthorhombic phase with large orthorhombic distortion appears and forms a mixture with the tetragonal phase. Superconductivity appears in the range of δ≳0.03. In the mixture range of δ≳0.08, however, the orthorhombic phase may exhibit no superconductivity due to the overdoping of hole carriers into the CuO2 plane. The maximum Tc increases up to ∼35 K, which is about 10 K higher than that obtained by annealing under high pressures of oxygen, owing to the larger hole concentration in the CuO2 plane.
AB - We have obtained La1.95Bi0.05CuO4+δ with various values of δ by the KMnO4 oxidation method. The largest value of δ≈0.136 is about twice as large as that obtained by annealing under high pressures of oxygen, δ≈0.056. A structural phase transition from the orthorhombic to the tetragonal phase with the increase of δ is observed at δ=0.035-0.04. For δ≳0.08, another orthorhombic phase with large orthorhombic distortion appears and forms a mixture with the tetragonal phase. Superconductivity appears in the range of δ≳0.03. In the mixture range of δ≳0.08, however, the orthorhombic phase may exhibit no superconductivity due to the overdoping of hole carriers into the CuO2 plane. The maximum Tc increases up to ∼35 K, which is about 10 K higher than that obtained by annealing under high pressures of oxygen, owing to the larger hole concentration in the CuO2 plane.
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U2 - 10.1016/0921-4534(95)00473-4
DO - 10.1016/0921-4534(95)00473-4
M3 - Article
AN - SCOPUS:0029774233
VL - 256
SP - 253
EP - 260
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 3-4
ER -