Studies on La2−xPrxCayBa2Cu4+yOz (x=0.1–0.5, y=2x) type mixed oxide superconductors

The La2−xPrxCayBa2Cu4+yOz (LaPrCaBCO) mixed oxides have been studied for their structural and superconducting properties using X-ray diffraction (XRD), d.c. resistivity, d.c. susceptibility and iodometric double titration techniques. The Rietveld analysis of the XRD data of all the LaPrCaBCO samples (x=0.1–0.5) exhibits that all the compounds crystallize in tetragonal R-123 type structure (space group P4/mmm). With the increase in x, Tc increases up to a maximum value of 58 K (x=0.5, La-2125 stoichiometry), which is interesting for Pr substituted high Tc oxides. The results of structural studies and superconducting property measurements are presented in light of increase in Tc in LaPrCaBCO system with increasing Pr concentration.