Spin dynamics and mode structure in nanomagnet arrays: effects of size and thickness on linewidth and damping

Published

May 5, 2009

Author(s)

Justin M. Shaw, Thomas J. Silva, Michael L. Schneider, Robert D. McMichael

Abstract

We use frequency resolved magneto-optic Kerr effect to probe the spin-dynamics and mode structure in 50 to 200 nm diameter Ni₈₀Fe₂₀ nanomagnets ranging from 3 to 10 nm in thickness. We find that the intrinsic Gilbert damping parameter is largely unaffected by the nanopatterning process despite a large linewidth dependence on the size of the nanomagnets. In the larger nanomagnets, both end and center mode are observed. The linewidth of these two modes differ considerably, which is most likely the result of the sensitivity of the end mode to small variations and imperfection of the shape and edge material. We show that this effect can be exploited as a means to separately characterize the magnetic properties of the nanomagnets as well as the size and shape variations within the array.

Citation

Physical Review B

Volume

79

Issue

18

Pub Type

Journals

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Keywords

nanodots, magnetodynamics, spin dynamics, nanostructures, ferromagnetic resonance, nanomagnets

Citation

Shaw, J. , Silva, T. , Schneider, M. and McMichael, R. (2009), Spin dynamics and mode structure in nanomagnet arrays: effects of size and thickness on linewidth and damping, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=33207 (Accessed October 9, 2025)