New chemical route for YBCO thin films

Sol-gel derived coating of YBCO film is very attractive for low cost as well as the ease of scalability. Among them, TFA-MOD using metal trifluoroacetates helps avoid the formation of BaCO₃ in the film. But this process has difficulties in optimizing the humid atmosphere to remove HF from the Y-Ba-Cu-O-F systems. So, in this work, another approach to chemical solution without fluorinated precursor was investigated. To make homogeneous stable solution, at first, YBCO powders were synthesized from organic solution containing Y₂O₃, BaCO₃, and CuO powders followed by calcination in air. Dip coatings were carried out from the solution of calcined YBCO powder dissolved into a mixture of methanol and propionic acid on LaAlO₃ [100] substrates. The coated film was annealed by reduced oxygen partial pressure. Dense, homogeneous and biepitaxially grown YBCO films were obtained from dip coating with ∼5 mm/s of drawing speed.