ANALYSIS AND PREDICTION OF THE CRITICAL-CURRENT DENSITY ACROSS [001]-TILT YBA2CU3O7-DELTA GRAIN-BOUNDARIES OF ARBITRARY MISORIENTATION ANGLES

A qualitative analysis of the expected dilatation rain field in the vicinity of an array of grain-boundary (GB) dislocations is presented. The analysis provides a basis for the prediction of the critical current densities (j(c)) across low-angle YBa2Cu3O7-delta (YBCO) GB's as a function of their energy. The introduction of the GB energy allows the extension of the analysis to high-angle GB's using established models which predict the GB energy as a function of misorientation angle. The results are compared to published data for j(c) across [001]-tilt YBCO GB's for the full range of misorientations, showing a good fit. Since the GB energy is directly related to the GB structure, the analysis may allow a generalization of the scaling behavior of j(c) with the GB energy.