Proximity effect in Fe/Pb/Fe trilayers

Abstract

74.80.Dm Superconducting layer structures: superlattices, heterojunctions, and multilayers , - 74.50.+r Proximity effects, weak links, tunneling phenomena, and Josephson effects , - 74.62.-c Transition temperature variations,

Proximity effect between superconductors and ferromagnets: from thin films to nanostructures

“…Using ξ S = 2ξ 0 /π = 57Å we obtain η = ξ F / ξ S ≈ 0.02. Similarly low values have also been reported for Nb/Gd [20,23] and Fe/Pb (η = 0.04) samples [27], where the values were found to be much smaller than the ones obtained from the conductivity ratio. For the Nb/Gd system, the different parameters η = 0.047 for evaporated samples [20] and η = 0.013 for sputtered samples [23] indicate a strong influence of the preparation method on η.…”

“…This has been discussed in detail by Lazar et al [51], based on an extended theory for finite interface transparency by Tagirov et al [52]. Third, the nonmonotonic behavior is completely suppressed if the spin-orbit scattering is strong compared to the ferromagnetic exchange interaction [17,27].…”

“…Although the measurements on sputtered Nb/Gd multilayers and triple layers have been interpreted in terms of this mechanism [23,24], the loss of ferromagnetic order at thin interlayer thicknesses [20] or a magnetically "dead" interface region can also result in a nonmonotonic behavior of T c (d F ) [26]. Furthermore, the magnitude of the electron mean free path l in S and F, the interface transparency, and spin-orbit scattering must be taken into account [17,18,27]. Clear evidence for π-coupling was obtained, inter aliter, from the nonmonotonic T dependence of the critical Josephson current in S/F/S structures [28].…”

Superconductor/ferromagnet proximity effect in Fe/Pb/Fe trilayers

“…14 However, the growth properties of the Pb/Fe layered system is rather problematic and due to a rather large roughness of the interfaces, our preliminary results on the Pb/Fe samples published in Ref. 15 were rather disappointing, not showing any oscillation in the T c (d Fe ) curve. In the meantime we were able to improve the structural quality of the Pb/Fe layered system definitely by optimizing the rf sputtering process.…”

Effect of superconducting spacer layer thickness on magneto-transport and magnetic properties of La0.7Sr0.3MnO3/YBa2Cu3O7/La0.7Sr0.3MnO3 heterostructures

“…It is also shown in Fe/Pb/Fe trilayers that above a particular thickness of the ferromagnetic layer, superconductivity gets suppressed due to the proximity effects, wherein pair-breaking effect of Cooper pairs occurs upon its penetration through the interface into the ferromagnetic side due to magnetic exchange field. 16 For understanding the transport mechanism occurring in metallic region in LSMO/YBCO/LSMO trilayers, the resistivity data were analyzed by using the equations [17][18][19] q ¼ q 0 þ q 2 T 2 þ q 4:5 T 4:5 ;…”