Superconducting tapes using ISD buffer layers produced by evaporation of MgO or reactive evaporation of magnesium

To avoid large angle grain boundaries in YBa2Cu3O7 (YBCO) thin films, biaxially textured buffer layers were grown by inclined substrate deposition. We use MgO as buffer layer material, which can be grown at rates up to 300 mm/min using either e-beam evaporation of MgO or reactive thermal evaporation of magnesium Employed substrates were Hastelloy C276 or stainless steel. Epitaxial YBCO was grown on these buffer layers by thermal co-evaporation. We reached YBCO in plane texture of 7 degrees FWHM and critical currents along tape direction of 84 A on tapes with 8 mm width and 1.8 mum YBCO thickness which means a current density of 0.58 MA/cm(2).