Fe/Cu superlattices exhibit a structural and magnetic transition with increasing Fe layer thickness, thus increasing the Curie temperature. An enhancement in the superconducting transition temperature is found in proximity coupled Nb/[Fe/Cu] layers as the Fe thickness increases. These results indicate a weakening of the magnetic proximity effect for the material with higher Curie temperature, and suggest a dominant role of spin-flip scattering in the pair breaking processes which give rise to the proximity effect.

• Received 5 November 1998

DOI:https://doi.org/10.1103/PhysRevB.59.14659