Electromagnetic properties of nickel-zinc and manganese-zinc ferrite doped opal matrices in millimeter waveband

Microwave properties of magnetic photonic crystals, namely, silica opal matrices doped with nickel- zinc or manganese-zinc iron spinels have been investigated in the frequency range from 26 to 38 GHz. The experiments were carried out using two methods: (1) the measurements of microwave absorption in a cavity resonator and (2) electromagnetic wave penetration through a sample placed into a waveguide. It has been found that these magnetic nanocomposites show resonance-type dependence of the transmission coefficient versus magnetic field. Magnetic resonance spectra have been studied. The resonance variations in the nickel-zinc ferrite-doped nanocomposite are up to 70% that enables to use that material in magnetic field driven microwave devices.