The limitation mechanism of Jc-θ characteristics in YBa2Cu3O7-x thin film with a single low angle grain boundary

The angular dependencies of critical current density (J(bc)) in a YBa2Cu3O7-x film on a bicrystal SrTiO3 substrate were measured. At low magnetic field, J(bc) was limited by the low angle grain boundary (LAGB), regardless of the angle, theta between the c-axis and magnetic field. However, the limitation mechanism of J(bc)-theta curves changed at kink positions in high magnetic field. The vortex pinning in the grains determined J(bc) for low theta, but J(bc) at high theta was still limited by the LAGB. The crossover of J(bc) limitation mechanism is discussed to understand the angular dependence of critical current in coated conductors. (C) 2007 Elsevier B.V. All rights reserved.