Abstract: A process for preparing a composition having the general formula REBa.sub.2 Cu.sub.4 O.sub.y where RE is a rare earth element such as dysprosium and including yttrium and the subscript "y" is about 8.0. The process utilizes nitric acid among the starting components to provide control over stoichiometry and minimize contamination. The present invention is also directed to a process of preparing a high purity superconductor utilizing the composition thus prepared. This process permits the superconductor to be prepared in a short time and at low sintering temperatures.

Abstract: This invention describes the way to prepare high purity Bi-based superconducting powders with the zero resistance temperature at 110K. The technique employs the dissolution of corresponding metal nitrates in deionized water, plus oxalic acid to chelate the metal cations. The amount of oxalic acid equals to about half of the total nitrate anion in molar ratio. After pH adjustment and gelation, optimal calcination results in 110K superconducting powders in high purity.