Superconductivity in sintered-polycristalline PrBa₂Cu₃O_(7-δ)

Superconductivity in thin films and powders, and in single crystals of Pr-123 has been found by Blackstead et al. and Zou et al., respectively. Nevertheless, up to now it has never been reported in sintered-policrystalline samples. We have prepared high-quality samples of this material by following a sol-gel method. We characterized the structure of all samples by using XRD and SEM-EDS techniques. Magnetic characterization was performed by measuring the magnetization as a function of the temperature T, and the applied magnetic field H. Measurements were taken in the ranges 2 K <T < 400 K and 0 <H< 5 Tesla. In this work we report by the first time superconductivity in Pr-123 sintered-polycristalline samples, with $T{_c}$ around 90 K, and $H{_c1}$ around 870 Oe.