Fabrication of high-critical current density YBa2Cu3O7-δ films using a fluorine-free sol gel approach

Superconducting YBa2Cu3O7-delta (YBCO) films with critical transition temperature T-c(0) of 90 K were fabricated via a fluorine-free, metal trimethylacetate based sol-gel route. Precursor films were spin-coated onto single-crystal (001) LaAlO3 (LAO) and (001) SrTiO3 (STO) substrates. Optimization of the burnout process resulted in films with excellent out-of-plane and in-plane texture. Transport critical current densities, J(c), of 1.6 and 1.1 MA/cm(2) were obtained at 77 K in self-field on films grown on LAO and STO substrates, respectively. This is the first demonstration of high-J(c) YBCO film fabrication using a fluorine-free, ex-situ process.