Electrodynamic Model and Calculation of the Effective Permeability Tensor for 3D Magnetic Opal-based Nanocomposites at Microwaves

The electrodynamic model of propagating of electromagnetic waves in 3D magnetic opal nanocomposites based on the solution of the Maxwell's equations with electrodynamic boundary conditions, complemented by the Landau-Lifshitz equation with the exchange term is developed by using the decomposition approach on autonomous blocks with Floquet channels. By solving the system of quasi-simultaneous equations the real and imaginary parts of the diagonal and off-diagonal components of the effective permeability tensor of the Ni0.7Zn0.3Fe2O4 particles-containing magnetic opal as a function of DC magnetic field were calculated at a frequency f = 26 GHz. The results of simulation taking into account the different number of ferromagnetic spherical nanoparticles, filling the octahedral SiO2 opal void regions, for the constant value of the filling factor show good agreement with the experimental data.