The superconducting and magnetic properties of a -Cox Si 1-x /Nb bilayers have been studied as a function of Co content in order to analyze the superconducting/ferromagnetic proximity effect in a system with strong disorder in the magnetic layers. As Co atoms become more diluted, the magnetization of the amorphous a -Cox Si1-x alloy decreases gradually, whereas their resistivity increases and enters in a weak localization regime. The superconducting transition temperatures of the a -Cox Si1-x /Nb bilayers follow a decreasing trend as Co content is reduced, reaching the lowest value at the boundary between the ferromagnetic-nonmagnetic amorphous phases. These results can be understood in terms of the increase in interface transparency together with the changes in the spin-flip scattering term as magnetic disorder increases and the amorphous a -Cox Si1-x layers loose their magnetic character.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 19 Nov 2010|