A method for producing a thick film includes disposing a precursor solution onto a substrate to form a precursor film. The precursor solution contains precursor components to a rare-earth/alkaline-earth-metal/transition-metal oxide including a salt of a rare earth element, a salt of an alkaline earth metal, and a salt of a transition metal in one or more solvents, wherein at least one of the salts is a fluoride-containing salt, and wherein the ratio of the transition metal to the alkaline earth metal is greater than 1.5. The precursor solution is treated to form a rare earth-alkaline earth-metal transition metal oxide superconductor film having a thickness greater than 0.8 μm. precursor solution.