Microwave complex permeability and permittivity of nanoferrites

Abstract

Complex permittivity and permeability of nanosized magnetic powders are studied for eight different bands to cover the frequency range from 2–40 GHz. A precise transmission-reflection based waveguide technique has been used to carry out measurements across the frequency bands. The algorithm for transmission and reflection calculations has been modified to account for variable sample thickness in the in-waveguide measurement setup. Diluted nanopowder sample has also been studied. The ferromagnetic resonance in nanoferrites has been observed to be sharper compared to microsized ferrites. Detailed analysis of measurement uncertainties and instrumentation errors has been performed.