Regensburg 2010 – scientific programme

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MA: Fachverband Magnetismus

MA 33: Poster II

MA 33.34: Poster

Friday, March 26, 2010, 11:00–14:00, Poster B1

Domain-wall types and switching fields in magnetic nanowires with perpendicular magnetic anisotropy determined by micromagnetic simulations — •Theo Gerhardt¹, Judith Moser¹, Andreas Vogel¹, André Kobs¹, Guido Meier¹, and Markus Bolte^1,2 — ¹Institut für Angewandte Physik, Universität Hamburg, Germany — ²Arbeitsbereich Technische Informatik Systeme, Department Informatik, Universität Hamburg, Germany

Magnetic multilayers with perpendicular magnetic anisotropy are a well known material system with potential application e.g. in storage concepts based on current-driven domain-wall motion [1]. We present a systematic investigation of the influence of the material parameters of a thin nanowire, i.e., saturation magnetization M_S, anisotropy constant K₁, and exchange constant A, on the domain-wall type and the switching field via micromagnetic simulations. For low K₁ and high M_S, the multilayers have in-plane magnetization, while for high K₁ and low M_S, the magnetization of the wire points out-of plane with Bloch walls separating the domains. At the phase boundary, Néel walls predominate. The switching fields are found to decrease with increasing M_S and decreasing K₁, but are much larger than in comparable experiments, even when edge roughness is considered in the simulations. By introducing a local variation of the material parameters, as was recently done in Ref. [2], good agreement with experimental data is achieved. [1] S. S. P. Parkin et al., Science 320, 190 (2008), [2] C. Burrowes et al., Nature Physics, Adv. Online Publication Nov. (2009), DOI:10.1038/NPHYS1436