Influences of the aspect ratio and film thickness on switching properties of elliptical permalloy elements

C. C. Chang, Y. C. Chang, W. S. Chung, J. C. Wu, Z. H. Wei, M. F. Lai, C. R. Chang

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The size dependence on the switching properties of microstructured Permalloy (Ni80Fe20) ellipses were investigated by magnetoresistance measurements and magnetic force microscopy. Elements with fixed short axes of 1 μm, long axes varying from 2 to 10 μm, and film thickness varying from 8 to 55 nm were fabricated by electron beam lithography through a lift-off technique. A single-domain configuration was observed in the elements with the range of aspect ratios (long/short axis) from 5 to 10. More complex domain structures appear in the lower aspect ratio and thicker samples. The switching properties show a strong dependence on the film thickness as well as the aspect ratio. The switching fields of uniform magnetization reversal increase with increasing thickness up to a critical value (24 < tc < 40 nm), whereas they decrease with increasing thickness above t c. Nevertheless, the switching fields only show weak dependency on aspect ratio.

Original languageEnglish
Pages (from-to)947-949
Number of pages3
JournalIEEE Transactions on Magnetics
Issue number2
Publication statusPublished - 2005 Feb 1


All Science Journal Classification (ASJC) codes

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

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