In representative cases, superconducting ceramics for use in accordance with the present invention may be prepared consistent with the stoichiometric formula (A1-x Bx)7 Cuz Ow, where A is one or more elements of Groups IIIa and Vb of the Periodic Table such as rare earth elements, B is one or more elements of Group IIa of the Periodic Table, e.g., the alkaline earth metals including beryllium and