Peculiarities of performance of the spin valve for the superconducting current

The spin valve effect for the superconducting current based on the superconductor/ferromagnet proximity effect has been studied for a CoO (x) /Fe1/Cu/Fe2/Cu/Pb multilayer. The magnitude of the effect Delta T (c) = T (c) (AP) - T (c) (P) , where T (c) (P) and T (c) (AP) are the superconducting transition temperatures for the parallel (P) and antiparallel (AP) orientation of magnetizations, respectively, has been measured for different thicknesses of the Fe1 layer d (Fe1). The obtained dependence of the effect on d (Fe1) reveals that Delta T (c) can be increased in comparison with the case of a half-infinite Fe1 layer considered by the previous theory. A maximum of the spin valve effect occurs at d (Fe1) d (Fe2). At the optimal value of d (Fe1) almost full switching from the normal to the superconducting state when changing the mutual orientation of magnetizations of the iron layers Fe1 and Fe2 from P to AP is demonstrated.