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Normal and superconducting properties of Pb2Sr2Y1−xCaxCu3O8+δ: II. Dependence on the oxygen concentration

✍ Scribed by Yoji Koike; Hiromu Sunagawa; Takashi Noji; Masahiro Masuzawa; Norio Kobayashi; Michiko Namiki; Kichinosuke Hirokawa; Yoshitami Saito

Publisher
Elsevier Science
Year
1990
Tongue
English
Weight
531 KB
Volume
171
Category
Article
ISSN
0921-4534

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✦ Synopsis

The dependence on the oxygen concentration of normal and superconducting properties of ceramic samples of Pb2Sr2Y~ _xCaxCu3Os+a has been investigated in the composition range of 0 _< x< 0.5 and 0_< fi< 2. The superconductivity in each sample with different x is suppressed with increasing ~, which is in good correspondence to the increase in resistivity and Hall coefficient with increasing ~, but is contradictory to the speculation by Ohta and Maekawa [Phys. Rev. B41 (1990) 6524 ]. It is found from chemical analysis that holes introduced by the extra oxygen first enter the CuO6 layer and then the PbO layer rather than the pyramidal CuO: layer. With increasing ~, a structural phase transition from the orthorhombic phase to the tetragonal phase is observed at ~~ 1 in every sample with different x. The dependence on the oxygen concentration of the magnetic susceptibility is also reported.

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