The superconducting and magnetic properties of oxygen-controlled-melt-grown (Nd, Eu, Gd)Ba2Cu3Oy (NEG-123) superconductors containing Pr in the concentration range x = 0 to 0.15 are reported. X-ray diffraction results confirmed the main phase as NEG-123 phase without any significant change in the crystal structure. Magnetization measurements revealed a depression of the superconducting transition temperature, Tc. The transitions are sharp at low Pr concentrations, however, a broad maximum begins to develop when the Pr concentration is x>0.1. The critical current densities, Jc, and the irreversibility fields are found to decrease on increasing the Pr content. It is also found that Jc of the Pr-doped composites for x = 0.12-0.15 is about five orders of magnitude lower than that of the pure NEG-123 composites. The fall in Tc and Jc on Pr doping is explained in terms of the partial substitution of Pr on the rare earth site and hole localization due to trivalent ions on the Ba site.
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