Direct growth of LaMnO₃ cap buffer layers on ion-beam-assisted deposition MgO for simplified template-based YBa₂ Cu₃O_7δ-coated conductors

Simplification of the ion-beam-assisted deposition (IBAD) buffer architecture is one of the key issues for reduced manufacturing cost of second-generation superconducting wire production. In this work, we studied various radio frequency magnetron sputter deposition conditions for epitaxial growth of LaMnO₃ (LMO) layers, with varying thicknesses, directly on IBAD-MgO without homo-epitaxial MgO layers. Performance of the simplified LMO/IBAD-MgO samples was qualified by pulsed-laser-deposited 1-μm-thick YBa₂CU₃ O_7-δ (YBCO) coatings. Detailed property characterizations revealed that though the growth temperature has a substantial effect on the texture of LMO layers, neither LMO thickness nor different sputter gas compositions had a significant effect on the performance of YBCO films. The superconducting properties of YBCO on LMO /IBAD-MgO are found to be similar to those obtained on templates having homo-epitaxial MgO layers. The present results underscore the strong potential of LMO as a single cap layer directly on IBAD-MgO for the development of a simplified IBAD architecture.