Growth and superconducting properties of YBa2Cu3O7−δ films on conductive SrRuO3 and LaNiO3 multilayers for coated conductor applications

Conductive multilayers of ${\mathrm{YBa}}_{\mathrm{2}}{\mathrm{Cu}}_{\mathrm{3}}{\mathrm{O}}_{\mathrm{7-\delta }}{\mathrm{/SrRuO}}_{\mathrm{3}}{\mathrm{/LaNiO}}_{\mathrm{3}}$ (YBCO/SRO/LNO), YBCO/SRO, and YBCO/LNO were grown epitaxially on single-crystal ${\mathrm{LaAlO}}_{\mathrm{3}}$ and ${\mathrm{SrTiO}}_{\mathrm{3}}$ substrates. Property characterizations revealed that the YBCO films on SRO and SRO/LNO buffer structures have excellent structural and superconducting properties. The YBCO/LNO, however, suffers degradation in superconducting transition temperatures and critical current densities, despite a good crystalline structure. The SRO/LNO bilayer showed excellent electrical contact with YBCO. These results have demonstrated the structural and chemical compatibility of SRO/LNO multilayers with YBCO and their potential use as conductive buffer layers for YBCO-based coated conductors as well as for other high-temperature superconducting applications.