Analysis of flux pinning in Y Ba2 Cu3 O7-δ films by nanoparticle-modified substrate surfaces

Enhanced in-field critical current density Jc has been achieved in Y Ba2 Cu3 O7-δ (YBCO) films grown on single crystal and biaxially textured metal substrate surfaces that were pretreated with second-phase nanoscale MgO and BaZr O3 particles. Nanoparticles were applied using wet chemical solution-based approaches. Results obtained in this study are compared with our previous investigations on surface modified substrates with sputter processed Ir nanoparticles. Cross-sectional TEM analysis and details of the field-orientation dependence of Jc are found to be similar for both sputtered and solution processed nanoparticle species. Present results show a more uniform dependence of Jc over all orientations of magnetic field, along with improved irreversibility behavior. Irrespective of the decoration technique, scaling behavior of the normalized volume pinning force density, Fp, demonstrates the similarity of pinning mechanisms for these YBCO films deposited on artificially modified substrates.