Magnetoresistance in an amorphous exchange-coupled bilayer
Résumé
The effect of a magnetic domain wall on the electronic transport in disordered materials is studied in an exchange-coupled amorphous Gd 40 Fe 60 / Gd 10 Fe 90 bilayer. In this amorphous system, the size and the shape of an interfacial domain wall is controlled by an external magnetic field. Current-in-plane transport measurements are performed on single GdFe layers, Gd 40 Fe 60 / Gd 10 Fe 90 bilayer, and on a Gd 40 Fe 60 / Si/ Gd 10 Fe 90 trilayer where the Si layer prevents the formation of the interfacial magnetic domain wall. Different contributions to the resistance are evidenced. In all types of samples, a linear positive magnetoresistance contribution is observed at high field which can be linked to the amorphous structure of the GdFe alloys. The comparison between the bilayer and the trilayer allows to eliminate this contribution and evidences that anisotropic mag-netoresistance is the main effect induced by the interfacial domain wall. Beyond the anisotropic magnetore-sistance signal, a supplementary negative magnetoresistance is evidenced. The origin of this effect is discussed qualitatively using previous theoretical predictions on magnetotransport through a magnetic domain wall in disordered metals.
Origine | Fichiers éditeurs autorisés sur une archive ouverte |
---|
Loading...