Ultra-high flux pinning properties of BaMO3-doped YBa2Cu3O7-x thin films (M = Zr, Sn)

We studied the flux pinning properties of BaZrO3-doped YBa2Cu3O7-x and BaSnO3-doped YBa2Cu3O7-x films. We found that BaSnO3-doped films showed very high global pinning forces, F-p, of 28.3 GN m(-3) ( 77 K, B parallel to c) and 103 GN m-3 ( 65 K, B parallel to c), twice that of BaZrO3-doped films. Transmission electron microscopy analysis showed that, in both films, nanorods of the dopant phase were incorporated. The BaSnO3 nanorods were nearly straight but the BaZrO3 nanorods became curved with the increasing film thickness.