INFLUENCE OF MAGNETISM ON SUPERCONDUCTIVITY IN EPITAXIAL FE NB BILAYER SYSTEMS/

We studied the superconductivity of molecular-beam-epitaxy-grown epita xial Nb(110) thin films covered by Fe(110) monocrystalline layers with thicknesses d(Fe) between 4 and 30 Angstrom. We find a nonmonotonous dependence of the superconducting transition temperature T-c on d(Fe), however, without a maximum in T-c(d(Fe)) as observed earlier in Nb/Fe layers prepared by sputtering techniques. We argue that the change in the T-c(d(Fe)) curve is caused by a smaller thickness of the nonmagne tic Fe-rich interlayer at the Nb/Fe interface and can be explained wit hin the same model developed previously for the explanation of the max imum in T-c(d(Fe)) in sputtered Nb/Fe layers.