Domain-wall contribution to magnetoresistance of a ferromagnetic (Ga,Mn)As layer

✍ Scribed by Wosiński, T. ;Figielski, T. ;Pelya, O. ;Mąkosa, A. ;Morawski, A. ;Sadowski, J. ;Dobrowolski, W. ;Szymczak, R. ;Wróbel, J.

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 235 KB
• Volume: 204
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200673230

✦ Synopsis

Abstract

Low‐temperature charge‐carrier transport in simple magnetoresistive nanodevices, consisted of narrow constrictions of submicron width in the epitaxial layer of a ferromagnetic (Ga,Mn)As semiconductor, has been investigated and correlated with magnetic properties of the layer. The devices containing constrictions revealed abrupt jumps of a reduced resistance that appeared when the sweeping magnetic field crossed the regions of the coercive field of the layer magnetization. In contrast, the non‐constricted reference device displayed abrupt jumps of an enhanced resistance at the same values of magnetic field. We interpret the both features, whose positions on the magnetic‐field scale reflect the hysteresis loop of magnetization, as manifestation of domain wall contribution to the (Ga,Mn)As layer resistance. The negative contribution of a domain wall to the resistance in the constricted device results most likely from the suppression of the weak localization effects by a domain wall located at the constriction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)