Superconducting and magnetic properties of Nb/Pd1-xFex/Nb triple layers
Physikalisches Institut, Universität Karlsruhe, 76128 Karlsruhe,
Revised: 26 April 1999
Published online: 15 March 2000
The superconducting and magnetic properties of Nb/Pd1-xFex/Nb triple layers with constant Nb layer thickness dNb = 200 Åand different interlayer thicknesses 3 Å≤dPdFe≤80 Åare investigated. The thickness dependence of the magnetization and of the superconducting transition temperature shows that for small iron concentration x the Pd1-xFex layer is likely to be in the paramagnetic state for very thin films whereas ferromagnetic order is established for x≥. The parallel critical field Bc2||(T) exhibits a transition from two-dimensional (2D) behavior where the Nb films are coupled across the interlayer, towards a 2D behavior of decoupled Nb films with increasing dPdFe and/or x. This transition allows a determination of the penetration depth of Cooper pairs into the Pd1-xFex layer as a function of x. For samples with a ferromagnetic interlayer is found to be independent of x.
PACS: 74.50.+r – Proximity effects, weak links, tunneling phenomena, and Josephson effects / 74.80.Dm – Superconducting layer structures: superlattices, heterojunctions, and multilayers / 75.70.Ak – Magnetic properties of monolayers and thin films
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000