Direct Observation of Remanent Magnetic States in Epitaxial fcc Co Small Disks

Published

April 1, 2003

Author(s)

C Vaz, L Lopez-Diaz, M Klaui, J Bland, T Monchesky, John Unguris, Z Cui

Abstract

The magnetic nanostructure of epitaxial fcc Co/Cu(001) circular elements (1.7υm in diameter) has been imaged with scanning electron microscopy with polarization analysis. The disks are obtained by ultrahigh vacuum deposition of the metal films onto a prepatterned Si(001) substrate. The Si structures are 700 nm high, ensuring that the continuous background film and that of the circular structures are not physically connected. A closed flux configuration (a quadrant configuration) is observed for some of the disks, characteristic of systems with cubic anisotropy. The measured width of the 90° domain wall varies from 70plus or minus}25 nm close to the vortex core, up to 150plus or minus}25 nm at a normalized distance r/r_dasymp} 0.625 from the vortex core (where r_d is the domain wall length from the vortex core to the disk periphery), i.e., significantly exceeding the bulk domain wall width, and increasing further with increasing distance from the vortex core. Such a wide domain wall is a consequence of the geometrical constraints imposed by the element, thus defining a geometrically constrained domain wall. This view is supported by detailed micromagnetic simulations that also show that the domain wall width increases dramatically with radial position from the disk center.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

67

Issue

14

Pub Type

Journals

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Keywords

disks, domain wall, micromagnetic, nanoscale, SEMPA, vortex

Citation

Vaz, C. , Lopez-Diaz, L. , Klaui, M. , Bland, J. , Monchesky, T. , Unguris, J. and Cui, Z. (2003), Direct Observation of Remanent Magnetic States in Epitaxial fcc Co Small Disks, Physical Review B (Condensed Matter and Materials Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=620550 (Accessed November 8, 2024)