Effects of gamma irradiation on the superconducting properties of TlBa ₂ Ca ₂ Cu ₃ O _x tapes

Abstract

Specimens of Tl-1223 superconducting tapes have been prepared using the powder-in-tube (PIT) method. Effects of gamma irradiation on the structure and transport properties of Tl-1223 tapes have been studied up to a gamma dose of 400 MR. A gradual decrease in the transition temperature and increase in the normal state resistance have been observed. A considerable decrease in the intensities of the major diffraction peaks of the XRD pattern was observed due to gamma irradiation. The I-V data were fitted to the power law V ~ I α (B,T) in which the power exponent α was found to increase gradually with gamma dose. The dependence of α on the temperature was studied and the effect of gamma irradiation on the pinning energy was discussed and explained in terms of the defects introduced on the grain boundaries, weak links, and Josephson junctions.