Epitaxial growth of Ba^2YNbO6 films on biaxially-textured NiW substrates as a multifunctional single buffer layer for high J c epitaxial YBCO film

Epitaxial Ba2YNbO6 (BYNO) films were deposited on textured NiW substrates via pulsed laser deposition. The films have dense and smooth surface structure, and more importantly, significantly improved out-of-plane texture, compared with the NiW substrate texture. Transmission electron microscopy study confirms the c-axis tilting of BYNO film and formation of misfit dislocations at NiW/BYNO interface, suggesting that the improved texture should be attributed to the tilted epitaxy via biased dislocation mechanism. YBa2Cu3O7-δ films deposited on BYNO single-buffered NiW substrates show further texture improvement, high superconducting transition temperature of ~91 K, and critical current density of 1.8 MA/cm² at 77 K, self-field.