Scaling of pinning forces in BaSnO3-added GdBa2Cu3O7 (- x) superconducting thin films

摘要

We have investigated the flux pinning force Fp in pure and 2 wt.% BaSnO3 (BSO)-added GdBa2Cu3O7, (GdBCO) superconducting films. Both pure and BSO-added GdBCO films with the thicknesses varying from 0.2 mu m to 1.5 mu m were prepared by using a pulsed laser deposition (PLD) technique. As BSO is added to the GdBCO films, two changes were observed in the field dependence of the pinning forces. First, the magnitude of the pinning force was greatly enhanced at each corresponding thickness. Second, the pinning forces exhibited an interesting plateau-like behavior. As a result, a universal scaling law of the pinning forces can be applied to the BSO-added GdBCO films which accounts for all variation in thickness. These results suggest an existence of an extra pinning mechanism through the film thickness which is induced by the formation of the BSO nanostructures. (C) 2017 Elsevier B.V. All rights reserved.