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 o, 3 o, 5 o and 7 o 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 o. PACS numbers (1999 scheme): 74.60.Jg, 74.50.+s, 74.76.Bz, 74.60.Ge 2 Well-aligned grains are necessary for optimum critical current density Jc in hightemperature superconductors. A large misalignment of adjacent grains suppresses the order parameter at the grain boundary (GB) and results in Josephson tunneling behavior  and a near-exponential decrease in Jc with misorientation angle [2–4]. In the case of YBa2Cu3O7−δ (YBCO) low-angle grain boundaries (θ � 4o), the boundary is comprised of
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.