Abstract: A process of manufacturing a superconducting compound including mixing stoichiometric amounts of a metallic oxide, copper oxide and a metallic carbonate wherein the metal of the metallic oxide is one other than yttrium and is selected and identified by its intrinsic massivity which is close in value to the intrinsic massivity of yttrium and wherein the interplanar distance on the C axis between Cu--O planes that exchange electrons through the electron-hopping mechanism in the ceramic perovskite is within the range of 1.97 .ANG. and 1.01 .ANG.. The mixture is subjected to pressure to form pellets and the pellets are then heated in forming the compound. The compound produced by the process and ceramic compositions having the formulas Mn Sr.sub.2 Cu.sub.3 O.sub.7-x and Mn.sub.2 Sr.sub.2 Cu.sub.3 O.sub.7-x.