Critical Current Density of YBa 2 Cu 3 O 7 − δ Low - Angle Grain Boundaries in Self - Field

A study has been perfomed on the superconducting critical current density Jc flowing across low angle grain boundaries in epitaxial thin films of YBa2Cu3O7−δ (YBCO). The materials studied were dual grain boundary rings deposited on SrTiO3 and containing 2 , 3, 5 and 7 tilt boundaries. The current density in self-field was determined by magnetometric methods at temperatures from 5 K to Tc. We conclude that at the higher temperatures of coated conductor applications, there is limited potential for improving Jc by reducing the grain boundary angle below ∼ 3. PACS numbers (1999 scheme): 74.60.Jg, 74.50.+s, 74.76.Bz, 74.60.Ge