Measurement of the nucleation and domain depinning field in a single Co/Pt multilayer dot by Anomalous Hall effect

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 7; pp. 1277 - 1280
• Main Authors: Delalande, M., de Vries, J., Abelmann, L., Lodder, J.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2012; Elsevier
• Subjects: Anomalous Hall Effect; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain nucleation; Domain structure (including magnetic bubbles); Domain walls; Exact sciences and technology; Hall effect; Halls; Magnetic data storage; Magnetic properties and materials; Magnetic properties of surface, thin films and multilayers; Magnetism; Multilayers; Nucleation; Physics; Platinum; Switches; Magnetic data storage; Domain nucleation; Anomalous Hall Effect; Magnetization reversal; Electron beam lithography; Domain walls; Anomalous Hall effect; Magnetic hysteresis; Cobalt; Multilayers; Magnetic storage devices; Anisotropy; Fine particle; Platinum; Magnetic domains; Transition elements; Angular variation; Wall pinning
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2011.09.037

Co/Pt multilayer dots with perpendicular anisotropy and with diameters of 250 and 350nm were fabricated on top of a Hall cross configuration. The angular dependence of the magnetic reversal of the individual dot was investigated by Anomalous Hall effect measurements. At near in-plane angles (85° with the magnetic easy axis) the dot switches partially into a stable two-domain state. This allows for separate analysis of the angular dependence of both the field required for nucleation of a reversed domain, and the field required for depinning of the domain wall. The angular dependence of the depinning field fits accurately to a 1/cos(θ) behavior, whereas the angular dependence of the nucleation field shows a minimum close to 45°. The latter dependency can be accurately fitted to the modified Kondorsky model proposed by Schumacher [1].
► Reversal takes place by nucleation and subsequent propagation of a domain wall. ► The domain wall can be trapped in the dot at near in-plane field angles. ► Angular dependence of depinning is accurately predicted by the Kondorsky model. ► Angular dependence of nucleation can be fitted to a modified Kondorksy model.