Controlled growth of YBCO film with tungsten oxide buffered substrate

Abstract

This study explores the influence of tungsten oxide (WO3-x) nanostructures, decorated on LaAlO3 (LAO) single crystal substrate, on the fabrication and superconducting performance of YBa2Cu3Oy (YBCO) films. The WO3-x in square-dot and nanowire forms, significantly enhance the biaxial texture of YBCO films, resulting in high critical current density Jc (square-dot, 3.05 MA/cm2 @ 77 K, nanowire, 2.1 MA/cm2 @ 77 K). However, the presence of WO3-x nanodots leads to a random nucleation of YBCO grains along the a/b-axis, driving a porous surface and broadening the full width at half maximum (FWHM) in both phi and omega scans. This poor texture deteriorates the film’s Jc to 0.71 MA/cm2 @ 77 K. Therefore, optimizing the WO3-x interface is crucial for enhancing the epitaxial growth and critical current density of YBCO film. This study provides an effective approach to optimize the superconducting performance of YBCO film by tailoring nanostructure interface.