Preparation of Y123 Thick Films by Fluorine-Free MOD Using a Novel Solution

It has been difficult to prepare Y123 films with a thick ness greater than 400 nm by using a single coating-preflring procedure in metal organic deposition (MOD), since shrinkage of the film causes cracks in the pyrolysis process. In the present study, we developed a novel coating solution for crack-free films with thicknesses greater than 500 nm. We used a Y-, Ba-, and Cu-acetylacetonate-based solution (metal content: ~2mol metal/L) with various additives for the coating solution. We prepared prefired films on CeO₂-buffered YSZ (CbYSZ) or CeO₂-buffered SrTiO₃ (CbSTO) substrates using the single coating-preflring process and this solution. When using some additives, we could obtain crack-free preflred films with thicknesses corresponding to 350-800 nm after crystallization to Y123. These prefired films were heat-treated at high-temperatures, resulted in epitaxial Y123 films. The J_c and I_c of the film on CbSTO was ~2.3 MA/cm² and 143 A/cm, respectively.