Investigation of the magnetic interaction of small permalloy particles

H. Koo, M. Dreyer, V. V. Metlushko, R. D. Gomez

Research output: Contribution to journalConference articlepeer-review

5 Citations (Scopus)


Permalloy island arrays and undulated lines were systematically studied by MFM to clarify the effect of neighbor magnetic interaction. The islands are 860 nm × 320 nm and 35 nm thick, single domains and patterned to have preferential interaction along the easy and hard axes. The switching field for easy axis interaction is relatively high, i.e., 370 Oe with a 32 Oe spread; while the hard axis interaction produces a switching field of 130 Oe and a slightly wider distribution of over 40 Oe. A third array is comprised of undulated lines with connected segments. Magnetic charges accumulate at the ends of each segment, and yield the strongest possible interaction along the easy axis. In this case all segments on one line simultaneously switch at a specific field. The switching field increases linearly from 150 Oe with the number of segments up to a maximum number of 50, and approaches a constant field of 290 Oe. The results favorably compare with the prediction for parallel rotation of the Jacobs-Bean chain of spheres model.

Original languageEnglish
Pages (from-to)2049-2051
Number of pages3
JournalIEEE Transactions on Magnetics
Issue number4 I
Publication statusPublished - 2001 Jul
Event8th Joint Magnetism and Magnetic Materials -International Magnetic Conference- (MMM-Intermag) - San Antonio, TX, United States
Duration: 2001 Jan 72001 Jan 11

Bibliographical note

Funding Information:
Manuscript received October 13, 2000; revised February 7, 2001. This work was supported in part by NSF CAREER AWARD ECS-9984797 H. Koo, M. Dreyer, and R. D. Gomez are with the Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742 USA. They are also with the Laboratory for Physical Sciences, College Park, MD 20740 USA (e-mail: V. V. Metlushko is with the Department of Electrical Engineering and Computer Science, University of Illinois, Chicago, IL 60607 USA. Publisher Item Identifier S 0018-9464(01)07278-8.


  • Array
  • Chain of spheres model
  • Jacobs-Bean model
  • Magnetic interaction
  • Parallel rotation
  • Permalloy
  • Switching distribution
  • Undulated line

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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