Interaction of teraherz radiation with 3D arrays of magnetic nanoparticle-filled carbon nanotubes

Background. The nanocomposites based on the 3D arrays of magnetic nanoparticle-filled carbon nanotubes (MNCNTs) are the advanced materials with interesting and potentially useful properties for future applications in the magnetically tunable devices at the teraherz frequency range. The aim of the present work is to theoretically research the interaction of teraherz radiation with the anisotropic nanostructured materials, based on the 3D arrays of magnetic nanoparticle-filled carbon nanotubes, using mathematical modeling at the electrodynamic accuracy level based on solving the Maxwell's equations, complemented by the Landau-Lifshitz equation. Materials and methods. The mathematical model of propagation and interactions of teraherz radiation with anisotropic nanostructured materials based on periodic 3D arrays of the of oriented magnetic nanoparticle-filled carbon nanotubes was developed by solving the characteristic equation for determining the wave propagation constants using a computational algorithm determining the conductivity matrix of autonomous blocks with Floquet channels (FABs). Results. The results of electrodynamic calculation of the real and imaginary parts of complex wave numbers of the fundamental mode of the clockwise, counterclockwise polarized electromagnetic waves and the ordinary, extraordinary modes, propagating in the 3D periodic arrays of the oriented magnetic Co$_{80}$Ni$_{20}$ nanoparticle-filled carbon nanotubes depending on the value and orientation of the DC bias magnetic field were obtained at frequency f = 1 THz. Conclusions. This work demonstrates that the effective permeability of the magnetic nanocomposites based on the 3D arrays of MNCNTs can be forecasted and designed taking into account the real structure (the geometry of array of MNCNTs; the arrangement of intercalated magnetic nanoparticles), opening a path to a new relationship between anisotropic nanostructured materials and CAD at the teraherz frequency range.