1000 A cm-1 in a 2 μm thick YBa2Cu3O7-x film with BaZrO3 and Y2O3 additions

We report here on significant improvements to the in-field and self-field critical current densities (J(c)) of multilayer and single-layer YBa2Cu3O7-x (YBCO) thick films with BaZrO3 (BZO) and Y2O3 additions. In the former case, the composite film consisted of a five-layer architecture with three YBCO layers and two Y2O3 interlayers in a total thickness of 1.8 mu m. The multilayer film produced a J(c) (75.6 K, self-field) of 4.3 MA cm(-2) (775 A cm(-1)) and a minimum J(c) (75.6 K, 1 T) of 1.0 MA cm(-2) (175 A cm(-1)) over all field orientations in the maximum Lorentz force configuration. We achieved in a single-layer 2.0 mu m thick film a J(c) (75.6 K, self-field) of 5.2 MA cm(-2) (1010 A/cm-w) and a minimum J(c) (75.6 K, 1 T) of 1.2 MA cm(-2) (234 A/cm-w) in the same measurement configuration. For both kinds of films, scanning transmission electron microscopy and transmission electron microscopy imaging were used to identify a uniformly dispersed second-phase microstructure consisting of short, tilted BZO nanorods and tilted Y2O3 nanoparticle layers. We attribute the enhanced performance of the thick YBCO films to the uniformity of the microstructure and the interaction of two different second-phase materials during film growth.