Tailoring defect microstructures for better magnetic flux pinning in YBa2Cu3O7−δ films using quench annealing

Strong magnetic flux pinning is required in many power-related applications of high-temperature superconductors. This has motivated us to explore a simple, robust way of tailoring defect microstructures in YBa2Cu3O7−δ (YBCO) films fabricated in situ using pulsed laser deposition. In this paper, we demonstrate that the defect microstructure in YBCO films can be greatly altered by quenching the film from the deposition temperature typically in the range of 700-800 °C to temperatures below the phase transition from the tetragonal to orthorhombic structures. The quench annealing has resulted in significantly improved magnetic flux pinning in YBCO films and is viable for large scale applications.