The Influence of the Polycrystalline State and Partial Dy Substitution on the Superconducting Properties of YBCO

The influence of the quasi-equal partial substitution of non-magnetic (Y 3+ )/magnetic (Dy 3+ ) ions in YBa 2 Cu 3 O 7-y on the superconducting properties of the material has been investigated. To minimize the influence of the stress field induced by lattice mismatch, Dy-substituted YBa 2 Cu 3 O 7-y was studied because Y 3+ and Dy 3+ ions have similar ionic radii. The investigation was performed on polycrystalline and powder samples with general formula Dy x Y 1-x Ba 2 Cu 3 O 7-y (x = 0.4-0.6). Higher magnetic losses and intragranular critical current density J c were observed for partially substituted samples in comparison with DyBCO. The strongest influence of magnetic substitution on the electrical resistivity properties was observed in the mixed state.