Process for forming metal oxide superconductors from a precursor material of the general formula YBa2Cu3(OH)3(Ox)2O3H2O (where Ox is an oxalate)

Metal oxide superconductors of the yttrium-barium-copper type can be formed by precipitation from an aqueous solution of the salts of the metals using an oxalate precipitation reagent under basic pH conditions to form a fireable precursor only partly in the form of the oxalate salts of these metals.