Techniques For Isolation And Electrical Characterization Of Individual Grain-Boundaries In Polycrystalline Superconductors

The electrical characterization of single grain boundaries in polycrystalline high-T(c) superconductors is a useful means for understanding the low critical current densities encountered in these materials. Various techniques, such as thinning, depositing of contact pads, bonding, mounting and patterning, for the preparation of samples with isolated grain boundaries are described and discussed. Preliminary results show that Josephson junctions as well as grain boundaries with flux pinning behaviour can be found.