Heavy ion irradiation effects on magnetic field dependent of losses in Bi-2212 single crystals

Abstract

We have studied the magnetic field dependent non-resonant rf losses in as-grown Bi2212 single crystals prior to and after irradiation with 250 MeV¹⁰⁷Ag¹⁷⁺ions. In the pristine state the losses from the inter-unit cell and intra-unit cell weak links are identified. The interesting feature is that the losses from inter-unit cell weak links reappear as the columnar tracks age with time suggesting that temperature cycling and thermal effects have important consequences on the robustness of the tracks. The losses from the intra-unit cell weak links although suppressed after irradiation, disappear suddenly at a certain temperature below T_c. This is unlike in the pristine state where the losses decrease smoothly as the temperature is decreased.