Samples of nominal composition (Bi2-xSbx)Sr2CaCu2Oy (0.1≤x≤0.3) are investigated. X-ray diffraction and electron diffraction show that the (Bi2-xSbx)Sr2CaCu2Oy system has a monoclinic phase with the lattice parameters a=21.73 A ̊, b=5.76 A ̊, c=19.32 A ̊ and β=95.0°, except for the tetragonal Bi-2212 phase. The results of energy dispersive X-ray spectroscopy reveal that Sb does not substitute for Bi in the Bi-2212 main structure, but forms the monoclinic phase of Bi4Sr4Ca2SbOy. The superconducting transition temperature, which is examined by electric resistance and AC magnet susceptibility, is constant at about 87 K. The reason why Sb cannot substitute for Bi in Bi2O2 layers has been discussed from the point of view of coordination.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering