Ordinary and triplet superconducting spin valve effect in Fe/Pb based systems

We report on experimental evidence for the occurrence of the long range triplet correlations (LRTC) of the superconducting (SC) condensate in the spin-valve heterostructures CoO_x/Fe1/Cu/Fe2/Pb. The LRTC generation in this layer sequence is accompanied by a T_c suppression near the orthogonal mutual orientation of the Fe1 and Fe2 layers' magnetization. This T_c drop reaches its maximum of 60mK at the Fe2 layer thickness d_Fe2 = 0.6 nm and falls down when d_Fe2 is increased. The modification of the Fe/Pb interface by using a thin Cu layer between Fe and Pb layers reduces the SC transition width without preventing the interaction between Pb and Fe2 layers. The dependence of the SSVE magnitude on Fe1 layer thickness d_Fe1 reveals maximum of the effect when d_Fe1 and d_Fe2 are equal and the d_Fe2 value is minimal. Using the optimal d_Fe1, d_Fe2 and the intermediate Cu layer we realized almost full switching from normal to SC state due to SSVE.