Effect of the variation of the exchange energy on the superconducting critical temperature of S/F/S trilayers

Abstract

The effect of the exchange energy variation in weakly ferromagnetic alloys on the superconducting resistive transition of superconductor /ferromagnet/superconductor (S/F/S) trilayers is studied. Critical temperature, Tc, and resistive transitions versus the F-layer thickness, dF , have been analyzed in Nb/Cu0.41Ni0.59/Nb and Nb/Pd0.81Ni0.19/Nb trilayers. We show that Tc(dF) dependence is sensitive to magnetic inhomogeneities in the F-layer for values of dF corresponding to thickness range where the π-superconducting state is established.