Nonmonotonic behaviour of superconducting critical temperature of Nb/CuNi bilayers with a nanometer range of layer thickness

Abstract

Present work reports the result of the proximity effect investigation for superconducting Nb/CuNi-bilayers with the thickness of the ferromagnetic layer (CuxNi1-x) being in the sub-nanometer range. It was found a non-monotonic behavior of the critical temperature, Tc , i.e. its growth with the increasing of the ferromagnetic layer thickness, dF , for the series of the samples with constant thicknesses of Nb layer, (dNb = const).