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Title: Magnetic instability regions in patterned magnetic structures : Influence of element shape on magnetization reversal dynamics.

Abstract

No abstract prepared.

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC); FOR
OSTI Identifier:
914823
Report Number(s):
ANL/XSD/JA-57138
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US200812%%89
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. Lett.; Journal Volume: 98; Journal Issue: Apr. 6, 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
36 MATERIALS SCIENCE; INSTABILITY; DEMAGNETIZATION; SHAPE; MAGNETIC MATERIALS; ELEMENTS; DYNAMICS

Citation Formats

Han, X. F., Grimsditch, M., Meersschaut, J., Hoffmann, A., Ji, Y., Sort, J., Nogues, J., Divan, R., Pearson, J. E., Keavney, D. J., Inst. voor Kern-en Stralingsfysica and INPAC, and Univ. Autonoma de Barcelona. Magnetic instability regions in patterned magnetic structures : Influence of element shape on magnetization reversal dynamics.. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.147202.
Han, X. F., Grimsditch, M., Meersschaut, J., Hoffmann, A., Ji, Y., Sort, J., Nogues, J., Divan, R., Pearson, J. E., Keavney, D. J., Inst. voor Kern-en Stralingsfysica and INPAC, & Univ. Autonoma de Barcelona. Magnetic instability regions in patterned magnetic structures : Influence of element shape on magnetization reversal dynamics.. United States. doi:10.1103/PhysRevLett.98.147202.
Han, X. F., Grimsditch, M., Meersschaut, J., Hoffmann, A., Ji, Y., Sort, J., Nogues, J., Divan, R., Pearson, J. E., Keavney, D. J., Inst. voor Kern-en Stralingsfysica and INPAC, and Univ. Autonoma de Barcelona. Fri . "Magnetic instability regions in patterned magnetic structures : Influence of element shape on magnetization reversal dynamics.". United States. doi:10.1103/PhysRevLett.98.147202.
@article{osti_914823,
title = {Magnetic instability regions in patterned magnetic structures : Influence of element shape on magnetization reversal dynamics.},
author = {Han, X. F. and Grimsditch, M. and Meersschaut, J. and Hoffmann, A. and Ji, Y. and Sort, J. and Nogues, J. and Divan, R. and Pearson, J. E. and Keavney, D. J. and Inst. voor Kern-en Stralingsfysica and INPAC and Univ. Autonoma de Barcelona},
abstractNote = {No abstract prepared.},
doi = {10.1103/PhysRevLett.98.147202},
journal = {Phys. Rev. Lett.},
number = Apr. 6, 2007,
volume = 98,
place = {United States},
year = {Fri Apr 06 00:00:00 EDT 2007},
month = {Fri Apr 06 00:00:00 EDT 2007}
}
  • We report a time-resolved imaging study of the influence of shape on magnetic instabilities in patterned magnetic structures. We find that in rectangular structures magnetization reversal initiates at the ends and interior simultaneously, while in structures with tapered ends the reversal begins in the middle of the structures and spreads out to the ends. The degree of tapering is important for both the switching field and the time required for full reversal. A model based on the concept of local instability regions yields good agreement with the observed location of the reversal onsets.
  • The magnetization reversal in patterned thin-film arrays of elliptical submicron permalloy elements has been investigated by magnetic-force microscopy and micro-magneto-optic Kerr effect. Three different spatial arrangements of chains are considered, namely chains aligned parallel to the long axis of the ellipse, chains aligned parallel to the short axis of the ellipse, and arrays with roughly equal element-to-element spacings in both directions. Comparison of the hysteresis loops in an in-plane field perpendicular to the ellipses' long axes shows that the magnetization reversibility is highest for chains along the long axis. This is due to the nearly coherent magnetization rotation in themore » applied magnetic field and to the formation of a head-to-tail domain arrangement. Other arrangements, such as chains of ellipses aligned parallel to short axis, yield flux-closure domains as the applied magnetic field is changed.« less
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  • No abstract prepared.
  • Pure magnetic patterning by means of ion-beam irradiation of magnetic thin films and multilayers often results from a postdeposition local modification of the interface structure with only minor effects on the film topography. In the study presented here a 60 keV fine-focused Co ion beam was used to change the coupling in a Ni{sub 81}Fe{sub 19}/Ru/Co{sub 90}Fe{sub 10} structure from antiferromagnetic to ferromagnetic on a micron scale. Thereby an artificial structure with locally varying interlayer exchange coupling and therefore magnetization alignment is produced. High-resolution full-field x-ray microscopy is used to determine the magnetic domain configuration during the magnetization reversal processmore » locally and layer resolved due to the element-specific contrast in circular x-ray dichroism. In the magnetically patterned structure there is, in addition to the locally varying interlayer exchange coupling across the Ru layer, also the direct exchange coupling within each ferromagnetic layer present. Therefore the magnetization reversal behavior of the irradiated stripes is largely influenced by the surrounding magnetic film.« less