Abstract:
Magnetic nanocomposites, composed of magnetic nanoparticles in an insulating matrix, can have
properties not achievable in bulk, single-phase materials. This work reports on ferromagnetic
resonance (FMR) measurements as a tool to investigate the internal magnetic field in nanocomposite
samples of varying particle packing fractions. The ferromagnetic resonance frequency changes with
particle packing fraction due to increased inter-particle interaction and demagnetizing field within the
sample. Experimental results obtained on NiFe2O4 nanocomposite samples are compared to
published theoretical models, and found to be consistent with the predicted trends. Extrapolation of
the results to the limit of isolated particles indicates an average internal anisotropy field of 0.041 T
for the NiFe2O4 nanoparticles.VC 2012 American Institute of Physics. [doi:10.1063/1.3679635]
