PROXIMITY EFFECT IN FE PB FE TRILAYERS

We have studied superconducting and magnetic properties of sputtered F e/Pb/Fe-trilayers. For a fixed Pb thickness d(Pb) and with changing Fe thickness, d(Fe), a monotonic decrease of the superconducting transit ion temperature T-c was observed. Magnetization measurements clearly s howed that Fe remains ferromagnetic down to the monolayer range. A qua ntitative comparison of T-c(d(Fe)) with the theory of pair breaking by the exchange field reveals that the observed T-c-suppression by the f erromagnetic Fe-layer is much weaker than expected. Possible reasons f or the reduced T-c-suppression in this system are discussed.