k-space spin filtering effect in the epitaxial Fe/Au/Fe/GaAs(001) spin-valve

Marie Hervé (1) , Sylvain Tricot (1) , Yann Claveau (1) , Gabriel Delhaye (1) , Bruno Lépine (1) , Sergio Di Matteo (1) , Philippe Schieffer (1) , Pascal Turban (1)

1 IPR - Institut de Physique de Rennes

The hot-electron magnetotransport of epitaxial Fe/Au/Fe/GaAs(001) spin-valves is investigated by ballistic-electron magnetic microscopy. A magnetocurrent amplitude larger than 500% is observed at room temperature close to the Schottky barrier energy. Remarkably, this magnetocurrent is not significantly affected by the thickness reduction of ferromagnetic films, down to 5 atomic layers of the Fe(001) top electrode. This rather suggests a dominant interfacial spin-filtering effect. Finally, the magnetocurrent is strongly reduced when the effective mass of the semiconductor collector is increased. These observations are consistent with recent theoretical prediction of k-space spin-filtering effect in epitaxial spin-valves attached to a semiconducting lead.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Marie Hervé, Sylvain Tricot, Yann Claveau, Gabriel Delhaye, Bruno Lépine, et al.. k-space spin filtering effect in the epitaxial Fe/Au/Fe/GaAs(001) spin-valve. Applied Physics Letters, 2013, 103, pp.202408. ⟨10.1063/1.4831755⟩. ⟨hal-00906297⟩