Vortex dynamics in YBaCuO single crystals with point- and line-like defects-flux creep studies

Studies of vortex dynamics and pinning were conducted in irradiated Y1Ba2Cu3O7 single crystals by observing the decay of supercurrents with time. The materials contained either point-like defects from proton irradiation or line-like defects from irradiation with energetic heavy ions. Analysis of the first case gives clear support for collective creep theory. With linear defects, the experiments give evidence for thermal smearing of the vortex pinning potential at higher temperatures, as predicted theoretically.