The structural and superconducting properties of R1-2xCaxThxBaSrCu3O7-delta (R = Eu or Dy; 0.0 <= x <= 0.1)

摘要

We have investigated the effect of simultaneous substitution of equal amounts of Ca2+ and Th4+ at the R site, on the structural and superconducting characteristics, in RBaSrCu3O7-delta (R = Eu or DY) by X-ray diffraction analysis, ac susceptibility, Je magnetization and de electrical resistivity measurements. A linear and sharp drop in T-c, with increasing dopant concentration x was observed in both the compounds despite the charge-conserving (presuming that R is in 3+ state) and non-magnetic nature of the dopants. The observed decrease can be attributed to the disorder induced in the compounds by doping. [References: 12]