A method for producing a superconductor by partial inter diffusion of layers of metal under a diffusion heat treatment to provide a ductile beta phase alloy, along with undiffused metal layers to permit ease of extrusion and drawing to fine layer thickness. At some point in the reduction the layers are further diffused to give an alloy superconducting product which is optimal for the high field (5-9 T) of interest in contact with a non-superconducting layer. This optimal diffusion is preferably accomplished after a sufficient reduction such that the individual metal layers are 2.5-15 microns thick.