Investigation on peak frequency of the microwave absorption for carbonyl iron/epoxy resin composite

Microwave absorbing characteristics of carbonyl iron/epoxy resin composite with various volume concentrations were investigated in 0.1-18 GHz. According to the electromagnetic parameters and thicknesses of the sample, numerical calculation and experiment have demonstrated that the frequency dependence of the microwave absorption comply with the quarter-wavelength (lambda/4) matching model that may explain not only the peak frequency but also the number of the peaks. It implies that the quarter wavelength condition can be successfully applied to understand and predict the peak frequency of the microwave absorption for ferromagnetic metal-based composites. (C) 2010 Elsevier B.V. All rights reserved.