Angular dependence of critical currents across YBa2Ca3O7-δ low-angle grain boundaries

The angular dependence of the transport critical current density Jc across an artificial 5 deg. [0 0 1]-tilt grain boundary (GB) in a YBa2Ca3O7-δ thin film was investigated. The magnetic field was rotated in the ab-plane of the film. Four intragrain tracks were available crossing the GB at 90 deg., 60 deg., 45 deg. and 30 deg. Flux channeling was found at all grain boundary tracks in a symmetric angular interval around the GB direction. The contribution of flux cutting to the critical current was evaluated for the 60 deg. track. Nearly no dependence on the applied magnetic field, but a strong variation with temperature was found