Water-vapor assisted photochemical fabrication of YBa2Cu3O7-x superconducting films with high critical current density

Abstract

A novel water-vapor assisted photochemical solution deposition method was put forward to fabricate high-performance YBa2Cu3O7-x (YBCO) superconducting films. The dip-coated gel films derived from YBCO solution with Y:Ba:Cu:F = 1:2:3:4 were exposed to deep UV light at a low temperature of 150 °C. During the UV exposure, water-vapor was artificially introduced to produce hydroxyl radicals (*OH) with strong oxidizing ability. After that, photon-activated amorphous oxide precursor films were obtained. It was found that the high-energy photons and *OH species promoted the cleavage of organic groups, enhanced the removal of residual organics, and improved the density of the YBCO films. Thus, YBCO superconducting films with improved superconducting properties were obtained after the crystallization process. The YBCO superconducting film that was UV-irradiated for 100 min with water vapor had a maximum critical current density (Jc) of 8.69 MA/cm2 (77 K and 0 T).