Enhanced random pinning with oxygen annealing in YBCO films prepared by large-area pulsed laser deposition

Abstract

We investigated the effect of oxygen annealing on the magnetic-field angular-dependent critical current density (Jc (θ)) in YBa2Cu3O7−x films deposited by large-area pulsed laser deposition. In an as-grown film, Jc (θ) exhibits a large maximum centered at , and a small one centered at . After oxygen annealing at 425 °C, the peak grew and surpassed the peak. We analyzed the Jc (θ) curves using the anisotropic scaling theory, and the result shows that mostly the peak due to random pinning increased with oxygen annealing. It is shown that the pinning center due to random defects is more sensitive to the oxygen content of the film.