Flux penetration into grain boundary of YBa 2Cu 3O 7- δ bicrystalline films with tilted surface

Effect of misorientation angle on the critical current density across [1 0 0] tilt grain boundaries (GB) in YBa ₂Cu ₃O _{7- δ} (Y123) thin films grown by liquid phase epitaxy method is investigated. The inter-granular critical current density, JcGB, was determined from a standard four-probe transport measurement. We also evaluated JcGB value by using a magneto-optical imaging technique to evaluate JcGB more directly. Both measurements showed higher JcGB for lower-angle GB, implying that GB with low misorientation angle has stronger coupling.