Preparation of high-temperature superconductors by controlled double-jet precipitation

Abstract Controlled double-jet precipitation has been used to synthesize high-temperature superconductors (HTSCs). The cation and oxalic anion solutions were simultaneously separately introduced into the crystallizer with a stirred solution of gelatin under conditions where the temperature, excess of oxalic anions in solution, pH, reactant addition rate, type and amount of the growth restrainer were tightly controlled. The suspensions with submicron average grain size, narrow grain size distribution, and with high sinterability were used to prepare bulk specimens and films on various substrates. The sintered oxides were characterized by electrical resistivity and ac-susceptibility measurement. The superconducting properties of these samples were found to be comparable, if not superior, to those observed for samples produced by other conventional methods.