Effects of 250 MeV Ag < sup > 17+ < /sup > ion irradiation on superconductivity in DyBa < inf > 2 < /inf > Cu < inf > 3 < /inf > O < inf > 7-δ < /inf > thin films

Abstract

We report the effect of 250 MeV Ag17- ion irradiation on DyBa2Cu3O7-δ thin films prepared by pulse laser deposition technique with fluences 5×1010, 1×1011, 5×1011 and 1×1012 ions/cm2. The SQUID measurements on irradiated films at 5, 35 and 77 K show that the film irradiated with a fluence of 1×1011 ions/cm2 shows a considerable improvement in critical current density, Jc, and pinning force density, Fp. The irreversibility field, Hirr, was estimated from the plot of normalized Fp vs the normalized field. A significant reduction in Hirr after irradiation and a dip in the plot of Hirr vs Bφ at a fluence of 5×1010 ions/cm2 were observed.