Epitaxial Growth of Solution-Based Rare-Earth Niobate, RE₃NbO₇, Films on Biaxially Textured Ni–W Substrates

A new series of rare earth-niobate, RE₃NbO₇ (RE=Y,Gd,Eu), buffer layers were developed for the growth of superconducting YBa₂Cu₃O_7−δ (YBCO) films on biaxially textured Ni–W (3 at.%) substrates. Using chemical solution deposition, smooth, crack-free, and epitaxial RE₃NbO₇ (RE = Y,Gd,Eu) films were grown on cube-textured Ni–W substrate. YBCO film with a critical current density of 1.1 × 10⁶ A/cm² in self-field at 77 K was grown directly on a single Gd₃NbO₇-buffered Ni–W substrate using pulsed laser deposition.