Transport in superconductor/ferromagnet/superconductor junctions dominatedby interface resistance - art. no. 064517

We report on high-sensitivity measurements performed on weakly resistive Nb /Al/Gd/Al/Nb ferromagnetic rare-earth-based junctions. High interface barri ers in such junctions can strongly modify interplay between ferromagnetism and superconductivity. We show in the present paper that fur such ferromagn etic/superconductor junctions that the main contribution to the resistance comes from interface scattering. On the other hand, measurements on identic al nonmagnetic rare-earth-based junctions such as Nb/Al/H/Al/Nb exhibit opp osite behavior; hence most resistance comes from the bulk. A theoretical de scription of the temperature dependence of the superconductor/ferromagnet/s uperconductor (S/F/S) junction resistance is given through a temperature de pendent Blonder-Tinkham-Klapwick theory for an energy range well below the superconducting gap scale of the Al/Nb bilayer. Such a theoretical descript ion proves that interfacial scattering is of crucial importance when experi menting in S/F systems using gadolinium.