Study of the effect of intrinsic and induced defects on the I-V characteristics of YBCO films

The current-voltage ? I-V . characteristics of YBCO films in zero applied magnetic field were investigated. Different conditions of fabrication have been considered in order to face with different structural defect configurations. The measurements were performed in a wide range of temperature, in the regime of thermal activation motion of magnetic vortices. The current-dependent activation energy for dissipative behavior was evaluated, and a correlation to the structural sample configuration was attempted. The results were compared to those obtained in Auq ion irradiated samples, where a regular distribution of artificial columnar defects is added to the background superconductor crystal defects. Two levels of irradiation were considered for the same sample.