Positive domain wall resistance in atomic-sized constrictions
Service de Physique de l'Etat Condensé, URA CNRS 2464, CEA Orme des Merisiers - F-91191 Gif-sur-Yvette, France, EU
Accepted: 14 March 2011
The magnetoresistance of a domain wall (DWR) is measured in Permalloy constrictions down to a few atoms in size. We find a negative DWR for nanometer-sized constrictions, becoming positive in the atomic-contact regime. We conclude that the contribution from the anisotropic magnetoresistance (AMR) is gradually weakened as size decreases and spin-polarized transport across an atomically narrow constriction dominates the magnetoresistance. This is revealed by a positive contribution to the DWR reaching four percent for the smallest constrictions, which depends significantly on the specifics of the atomic arrangement.
PACS: 72.25.Ba – Spin polarized transport in metals / 72.15.Gd – Galvanomagnetic and other magnetotransport effects / 73.23.Ad – Ballistic transport
© EPLA, 2011