Electromagnetic waves attenuation in composite with Fe nanoparticles

Metal-dielectric nanocomposites containing spherical Fe particles in an epoxyamine matrix were synthesized. The average diameter of the particles is about 60 nm, their weight fractions in the composites are from 15 wt% to 30 wt%. Magnetic and microwave properties of the composite were measured. In the field dependences of the transmission and reflection coefficients, there are the minima caused by the ferromagnetic resonance. A model of dynamic magnetic permeability is constructed, and the components of the permeability tensor are determined. The field dependences of the transmission and reflection coefficients, as well as microwave power dissipation, are calculated and compared with the measured ones. Qualitative and, in some cases, quantitative correspondence between the measured and calculated dependences is obtained. Analysis carried out has shown that the low field absorption (LFA) is not realized in the considered composites.