Upper critical magnetic fields of the Bi1.6Pb 0.4Sr2Ca2Cu2+xOy system with x=0.8, 1.2, 1.6 were measured by a magnetoresistance method using a pulsed magnetic field. The Hc2(0) are estimated to be 45.9, 218 and 64.9 T for x=0.8, 1.2, 1.6, respectively. Hc1(T) for each composition was determined from magnetisation curves. The superconducting parameters xi , kappa and lambda were derived from experimental data. X-ray diffraction patterns show that there is no obvious change in structure. It is suggested that the coordination number of Cu strongly influences the superconductivity.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics