Study of the possibility of realization of a spin valve on the basis of superconductor/ferromagnet multilayers

Abstract

The ways of realization of two different schemes of a spin valve for the superconducting current on the basis of the superconductor/ferromagnet proximity effect are studied. First, we have studied the superconducting proximity effect in the thin film system Fe/Cr/V/Cr/Fe where the Cr layers play the role of screening layers between the superconducting V-layer and the strongly pair breaking Fe-layers. Besides the new results concerning the magnetic phase transitions in the Cr layers we found the upper limit of the thickness of the screening Cr layers for operation a spin valve based on the Fe/V/Fe trilayer. Second, we studied the superconducting spin valve effect of a V-layer coupled to an antiferromagnetic [Fe/V]-superlattice. The parallel upper critical magnetic field exhibits an anomalous temperature dependence up to the ferromagnetic saturation field of the superlattice, indicating that the superconducting transition temperature Tc decreases when rotating the relative magnetization directions of the sublattice from antiparallel to parallel. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.