We measured microwave permeability in thermal annealed CoFe/MnIr bilayers. The ferromagnetic resonance frequency (fFMR) and Gilbert damping constant (αG) are analyzed using the Landau-Lifshitz-Gilbert equation. The fFMR increases with the exchange bias field, and it can be easily tuned over 10 GHz either by controlling the CoFe thickness or through modifications of unidirectional anisotropy by thermal annealing. The extracted αG is inversely proportional to the exchange bias field, and this behavior is caused by the suppression of the anisotropy field distribution due to an increase in the exchange bias field. Thus, low loss performance in microwave frequency range can be achieved in exchange biased CoFe/MnIr bilayers.
|Number of pages||4|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 2007|
|Event||International Symposium on Advanced Magnetic Materials and Appilications, (ISAMMA 2007) - Jeju, Korea, Republic of|
Duration: 2007 May 28 → 2007 Jun 1