title: Domain wall pinning in narrow ferromagnetic ring structures probed by magnetoresistance measurements.
abstract: We present a magnetoresistance study of magnetization reversal and domain wall pinning effects in a mesoscopic narrow ferromagnetic Permalloy ring structure containing notches. The size and strength of the attractive pinning potential created by a notch is measured and the resistance minimum at remanence is found to occur when a single transverse domain wall is pinned at the notch, in agreement with the results of numerical simulations of the anisotropic magnetoresistance. When a field is applied in the direction corresponding to a potential well edge, a novel magnetic state with a very wide domain wall is stabilized, giving rise to a characteristic signature in the magnetoresistance at such angles.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 OHE, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Kläui
authors.forename: C A F
authors.initials: CA
authors.lastname: Vaz
authors.forename: J
authors.initials: J
authors.lastname: Rothman
authors.forename: J A C
authors.initials: JA
authors.lastname: Bland
authors.forename: W
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: G
authors.initials: G
authors.lastname: Faini
authors.forename: E
authors.initials: E
authors.lastname: Cambril