Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 54: Superconductivity: Heterostructures
TT 54.5: Vortrag
Mittwoch, 18. März 2015, 10:45–11:00, H 3005
Superconducting Spin Valve Effect in Fe/In based heterostructures — •Pavel Leksin1, Nadir Garifyanov2, Ilgiz Garifullin2, Joachim Schumann1, Vladislav Kataev1, Oliver Schmidt1, and Bernd Büchner1 — 1Leibniz Institute for Solid State and Materials Research IFW Dresden, DE-01171 Dresden, Germany — 2Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan, Russia
We report on magnetic and superconducting properties of the spin-valve multilayer system CoOx/Fe1/Cu/Fe2/In. The Superconducting Spin Valve Effect (SSVE) assumes the Tc difference between parallel (P) and antiparallel (AP) orientations of the Fe1 and Fe2 layers’ magnetizations. The SSVE value oscillates and changes its sign when the Fe2 layer thickness dFe2 is varied from 0 to 5 nm. The SSVE value is positive, as expected, in the range 0.4 nm ≤ dFe2 ≤ 0.8 nm. For a rather broad range of thicknesses 1 nm ≤ dFe2 ≤ 2.6 nm the SSVE has negative sign assuming the inverse SSVE. Moreover, the magnitude of the inverse effect is larger than that of the positive direct effect. We attribute these oscillations to a quantum interference of the cooper pair wave functions in the magnetic part of the system. For most of the spin-valve samples from this set we experimentally realized the full switching between normal and superconducting states due to direct and inverse SSVE. The analysis of the experimental data has enabled the determination of all microscopic parameters of the studied system [1].
[1] P. V. Leksin et al., Phys. Rev. B 85, 024502 (2012).