Magnetic vortex domain wall observation on polycrystalline imperfect iron-cobalt alloy nanowires growing on 1050 Aluminum

C.L. LONDOÑO-CALDERÓN; A. LONDOÑO-CALDERÓN; O. MOSCOSO-LONDOÑO; A. GALINDO; A. PONCE; R. MARTÍNEZ-GARCÍA; M.JOSE-YACAMÁN; M. KNOBEL

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2022 vol. 219 p. 2100265 - 2100278

1862-6300

The design and studies of the physical properties of magneticnanowire arraysarea hot topic subject owing to their promising applications in a broadnumber of fields. The strong dependence of the nanowires? size, microstructure, and composition, with the physicochemical properties, leads to big changes in the macroscopic magnetic behavior. In this work, we study the magnetic vortex domain wall propagation via localized curling on iron-cobalt alloy nanowires. Moreover, we demonstrated that the pulsed electrodeposition of iron-cobalt atomsonto anodized low purity aluminum (AA1050) leads to the formation of imperfect multisegmented granola bar-like nanowire arrays. The results are analyzed and correlated to the crystalline structure, morphology, and elemental composition. The pore widening time of anodized aluminum was optimized for growing nanowires with 25 nm in diameter and 3 μm in length. The magnetic properties were analyzed by means of magnetometry and off-axis Electron Holography.The electrodeposited nanowire arrays have a homogeneous elemental composition (Fe67Co33); and exhibit a multisegmented polycrystalline structure composed by small crystallites (granola bar-like). The saturation magnetization, coercive field, and reduced remanence measured in directions parallel and perpendicular to the nanowire?s axis were studied as a function of the temperature. Although the nanowires on anodized AA1050 Al growing sloped and straight way, these present a high shape magnetic anisotropy, which is the most predominant contribution of the magnetic behavior.The presence of imperfections and misalignments on the nanowires, and the wide distribution of lengths and diameters do not lead to a coercivity distribution. A modified model taking into account the imperfections of the wire and the magnetostatic interactions is proposed to explain the changes of coercivity and magnetic behavior of the nanowire arrays. The reversal magnetization that occurs through vortex domain wall propagation via localized curling, which was confirmed by off-axis electron holography.