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Publication Citation: Ferromagnetic resonance linewidth in metallic thin films: Comparison of measurement methods

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Author(s): Sangita S. Kalarickal; Pavol Krivosik; Mingzhong Wu; C E. Patton; Michael Schneider; Pavel Kabos; Thomas J. Silva; John P. Nibarger;
Title: Ferromagnetic resonance linewidth in metallic thin films: Comparison of measurement methods
Published: May 22, 2006
Abstract: Strip line (SL), vector network analyzer (VNA), and pulsed inductive microwave magnetometer (PIMM) techniques were used to measure the ferromagnetic resonance (FMR) linewidth for a series of Permalloy films with thicknesses of 50 and 100 nm. The SL-FMR measurements were made for fixed frequencies from 1.5 to 5.5 GHz. The VNA-FMR and PIMM measurements were made for fixed in-plane fields from 1.6 to 8 kA/m (20-100 Oe). The results provide a confirmation, lacking until now, that the linewidths measured by these three methods are consistent and compatible. In the field format, the linewidths are a linear function of frequency, with a slope that corresponds to a nominal Landau-Lifshitz phenomenological damping parameter α value of 0.007 and zero frequency intercepts in the 160-320 A/m (2-4 Oe) range. In the frequency format, the corresponding linewidth versus frequency response shows a weak upward curvature at the lowest measurement frequencies and a leveling off at high frequencies.
Citation: Journal of Applied Physics
Volume: 99
Issue: 093909
Pages: pp. 1 - 7
Keywords: damping;FMR;magnetodynamics;PIMM
Research Areas: Electromagnetics
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