Phase-separated, epitaxial, nanostructured LaMnO₃+MgO composite cap layer films for propagation of pinning defects in YBa₂Cu ₃O₇δ coated conductors

Nanostructural modulation in the cap layer used in coated conductors can be a potential source for nucleating microstructural defects into the superconducting layer for improving the flux-pinning. We report on the successful fabrication of phase separated, epitaxial, nanostructured films comprised of LaMnO₃ (LMO) and MgO via pulsed laser deposition (PLD) on biaxially-textured MgO metallic templates with a LMO buffer layer. Scanning Auger compositional mapping and transmission electron microscopy cross sectional images confirm the nanoscale, spatial modulation corresponding to the nanostructured phase separation in the film. YBa₂Cu₃O ₇-δ films (0.8 μm thick) grown using PLD on such phase separated, nanostructured cap layers show reduced field dependence of the critical current density with an α value of ̃0:38 (in J_c ̃ H_-α).