A layered composition of a Cu-containing ceramic superconductor layer and a Ag-containing layer having between about 0.1 and about 0.3 atom percent Cu. The ceramic superconductor may be in contact with the Ag-containing copper doped layer which may be one or more of a substrate, a stabilizer or a sheath. Oxide superconductors are preferred.
 The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the U.S. Department of Energy (DOE) and The University of Chicago representing Argonne National Laboratory.