Epitaxial thin films of ${\mathrm{Bi}}_2{\mathrm{Sr}}_2{\mathrm{Ca}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{10+\delta }$ have been prepared by pulsed laser deposition on ${\mathrm{SrTiO}}_3$ bicrystal substrates with symmetrical [001] tilt grain boundaries of $8°,$ $16°,$ $24°,$ $26°,$ $30°,$ and $36.8°$ misorientation angle. The intergrain and intragrain properties of the critical current density and the current-voltage characteristics have been investigated at various temperatures and in magnetic fields up to 7.5 T. The $8°$ grain boundary exhibits flux creep behavior; it does not constitute a weak link. In contrast, grain boundaries with larger angles exhibit weak link behavior. The critical current density falls exponentially with increasing misorientation angle.

• Received 17 September 2001

DOI:https://doi.org/10.1103/PhysRevB.65.052507