RECOVERY OF SUPERCONDUCTIVITY IN THE WATER DEGRADED YBCO SAMPLES. Sandeep Rekhi, G. L. Bhalla, G. C. Trigunayat, Department of Physics & Astrophysics, University of Delhi, Delhi-110 007, India

The recovery of superconductivity in the water degraded samples have been studied by first subjecting them to heat treatments and then estimating possible recovery of superconductivity in them through structural, electrical, magnetic, and morphological investigations. The results reveal the transformation of secondary phases formed during degradation into YBCO phase. The presence of some additional phases of YBCO, possibly arising from deficiency of the constituent elements resulting from degradation/lack of proper reaction between the secondary phases, are also observed. The heat treatment carried out in a sample after pulverising it led to full recovery of superconductivity in it. A possible mechanism for the observed recovery of superconductivity has been suggested.