The transition temperature Tc and upper critical field Hc2 of sputtered Fe/Nb trilayers and multilayers have been determined by measurement of electrical resistivity. For a fixed Fe layer thickness, Tc decreases with decreasing Nb thickness up to a critical thickness dNb crit ≈ 34 nm below which superconductivity vanishes. When the superconducting layers are thin ( dNb < 140 nm ) and decoupled by pair breaking in the ferromagnetic layers, the parallel critical field exhibits nonlinear temperature dependence, revealing a change in the superconducting dimensionality. The strong decrease of Tc with decreasing Nb thickness as well as the temperature dependence of Hc2 can be well described by theoretical model.
|Journal||Journal of Magnetism and Magnetic Materials|
|State||Published - 1 Sep 2006|
- Critical thickness
- Dimensional crossover
- Proximity effect