The reactants produced at the start of the reaction of YBC with water include Y2O3, Ba(OH)2, BaCu(OH)3, and Cu2O. The compound Ba(OH)2 changes to form BaCO3, BaC2O4, and Ya(COOH)2 by reacting with CO2 present in the water. Compounds such as BaCuO2, CuO, and Y2BaCuO5 were then produced by reactions among such reactants as Y2O3, Ba(OH)2, BaCu(OH)3, and Cu2O.