Critical Current of Bicrystal of High-Temperature Superconductor with Low-Angle Tilt Boundary [001]

Dependence of the critical current on the misorientation angle in high-temperature superconductor [001]-tilt bicrystal is theoretically examined. As argued, in the case of relatively small values of the bicrystal misorientation angle theta (theta <= 10-15 degrees), both the critical current and the resistive-state appearance are determined by depinning of Abrikosov vortices, which are locked by edge dislocations aligned along the bicrystal-grain boundary. Dependence of the depinning critical current on the misorientation angle of bicrystal is determined, and it reveals a good agreement with experimental data obtained for Y-Ba-Cu-O bicrystals with [001]-tilt low-angle grain boundaries.