Superconducting properties of ceramic samples Pb2Sr2Y1−xCaxCu3O8+δ have been investigated in the wide composition-range of 0≦x≦0.8 and 0≦0<2. For samples of δ=0, Tc appears with compositions of x≧0.15 and takes a maximum at x=0.5. This is discussed in relation to x dependences of the electrical resistivity. the Hall coefficient, the upper critical field and the activation energy of the resistance tail in magnetic fields. As for samples of δ≠0, the superconductivity in each sample with different x is suppressed with increasing δ. which is in good correspondence to the increase in resistivity and Hall coefficient with increasing δ, but is contradictory to the speculation by Ohta and Maekawa.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering