title: Influence of internal geometry on magnetization reversal in asymmetric permalloy rings.
abstract: We report the magnetization reversal behavior of microstructured Ni80Fe20rings using magneto-optic indicator film imaging and magnetometry. While the reversal behavior of rings with a symmetric (circular) interior hole agrees with micromagnetic simulations of an onion → vortex → onion transition, we experimentally demonstrate that rings possessing an elliptical hole with an aspect ratio of 2 exhibit complex reversal behavior comprising incoherent domain propagation in the rings. Magneto optic images reveal metastable magnetic configurations that illustrate this incoherent behavior. These results have important implications for understanding the reversal behavior of asymmetric ferromagnetic rings.
authors.affiliation: Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Gopman
authors.affiliation: Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA; Institute for Solid State Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region 142432, Russia.
authors.forename: Y P
authors.initials: YP
authors.lastname: Kabanov
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 90095 CA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 90095 CA, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Lynch
authors.affiliation: Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Shull