Preparation of by the Oxalate Coprecipitation Method and its Powder Characterization

The oxalate coprecipitation method was applied to the preparation of high-T_c superconducting oxide powder. The process of forming the oxide through the pyrolysis and subsequent heat treatment was studied in connection with powder characterization. The oxalate copreciptate, being fine powder with in size, consisted of Y-Ba complex and Cu oxalates. The pyrolysis proceeded mostly by three steps in the order of dehydration, decomposition of Cu oxalate and that of Y-Ba oxalate, resulting in CuO and BaC0₃phases at 500*0 for 2h without changing particle shape. Heat treatment avobe 850*0 was favorable to obtain the oxide powder with single phase. Its particles were less than 2jum in size when treated below 9250 and drastically grew to more than 10/4. above 950°C with plate-like shape.