Fabrication of high JcYBa2Cu3O7-δ tapes using the newly developed lanthanum manganate single buffer layers

High J_cYBa₂Cu₃O_7-δ (YBCO) films have been fabricated on LaMnO₃ buffered ion-beam assisted deposition (IBAD) MgO template layers. A LaMnO₃ buffer layer is compatible with MgO surfaces and also provides a good template for growing high current density YBCO films. LaMnO₃ buffer layers were deposited using rf magnetron sputtering. On LaMnO₃-buffered-MgO [100] single crystal substrates, YBCO films with a J_c of over 4 M/cm² were grown using both pulsed laser deposition (PLD) and ex-situ BaF₂ process. Using PLD, J_c of 1.8 MA/cm² at 77 K was obtained on 200-nm-thick YBCO films grown on LaMnO₃-buffered MgO IBAD/Ni-alloy substrates. In addition, an I_c of 230 A/cm-width was obtained for 1.65-μm-thick YBCO films grown on LaMnO₃-buffered MgO IBAD/Ni-alloy substrates using PLD at Los Alamos National Laboratory. This performance is comparable to the best single-layer results achieved on IBAD-MgO substrates.