Nano-structures based on superconducting Nb and ferromagnetic CuNi alloy for elaboration of spin-valve core

Abstract

The main goal of our research group is the elaboration of superconducting spin-switch (valve) based on Ferromagnetic/Superconductor/Ferromagnetic core. We could realize all building blocks necessary for the fabrication of the core structure of the superconducting spin valve, consisting of two mirror symmetric bilayers [4]. In other words, the spin valve consists of a F/Š/F trilayer, which can be regarded as a package of a F/S and S/F bilayer so that Š=2S in the trilayer [16, 17]. For such a trilayer, the theory [4] predicts that the critical temperature depends on the relative orientation of the magnetization of the ferromagnetic layers. To enable a reversal of one of the magnetizations of the layers with respect to the other by an external magnetic field, the coercive forces of the F layers have to be different due to either intrinsic properties or to an antiferromagnetic pinning layer delivering an exchange bias. The main points of our study are presented here.