We investigate high-field ferromagnetic resonance of superparamagnetic particles with uniaxial anisotropy. In this case, since the field is large enough to saturate the magnetization, the thermal orientational fluctuations of the magnetic moment of the particle are negligible. Thus, we derive the dynamic susceptibility of the system on the basis of an independent particle model. High-field ferromagnetic resonance has been performed on fine cobalt particles. The analysis of the spectra obtained at different frequencies allows us to estimate the effective magnetic anisotropy, the gyromagnetic ratio, and the transverse relaxation time.
- Fine particles
- High-field ferromagnetic resonance
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering