Nemes, Norbert MarcelGarcía Hernández, M.te Velthuis, S. G. E.Hoffmann, A.Visani, C.Garcia Barriocanal, JavierPeña, V.Arias Serna, DiegoSefrioui, ZouhairLeón Yebra, CarlosSantamaría Sánchez-Barriga, Jacobo2023-06-202023-06-202008-091098-012110.1103/PhysRevB.78.094515https://hdl.handle.net/20.500.14352/51403© 2008 The American Physical Society. This work was supported by MAT 2005 under Contract No. 06024 C02 01-02, the Joint US-Spain World Materials Proposal NSF MWN Proposal DMR Contract No. 0709584 and MEC MAT 2007 Contract No. 30922-E, and by the US-DOE BES under Contract No. DE-AC02-06CH11357. N.M.N. acknowledges the “Ramon y Cajal” contract of the MICINN.We studied ferromagnet/superconductor/ferromagnet trilayers based on La_(0.7)Ca_(0.3)MnO_(3) manganite and YBa_(2)Cu_(3)O_(7−δ) (YBCO) high-T_(c) cuprate with magnetoresistance and magnetization measurements. We find an inverse superconducting spin-switch behavior, where superconductivity is favored for parallel alignment of the magnetization in the ferromagnetic layers. We argue that this inverse superconducting spin switch originates from the transmission of spin-polarized carriers into the superconductor. In this picture, the thickness dependence of the magnetoresistance yields the spin-diffusion length in YBCO as 13 nm. A comparison of bilayers and trilayers allows ruling out the effect of the stray fields of the domain structure of the ferromagnet as the source of the inverse superconducting spin switch.engjournal articlehttp://dx.doi.org/10.1103/PhysRevB.78.094515http://journals.aps.org/open access537SuperconductorFerromagnetJunctionsImbalance.ElectricidadElectrónica (Física)2202.03 Electricidad