The electric properties of low-magnetic-loss magnetic composites containing Zn-Ni-Fe particles

Recently, magnetic composites consisting of magnetic particles dispersed in a polymer matrix have been widely discussed for miniaturizing high-frequency electronic components such as antennae. Previously, we investigated the influence of the manufacturing process on the homogeneous dispersion of magnetic particles in the polymer and on the magnetic properties of the magnetic composites. In order to miniaturize electronic components, it is crucial to be able to independently control the permeability and permittivity in magnetic composites. This paper investigates the anisotropy and frequency dependence of the dielectric properties of magnetic composites fabricated from 20vol% Zn ₅Ni₇₅Fe₂₀ flaked particles. The permittivity of magnetic composites fabricated from Zn₅Ni₇₅Fe ₂₀ flaked particles is anisotropic: at 1GHz, the relative permittivities parallel and perpendicular to the plane of the specimens are 27.2 and 16.9, respectively. The permittivity varied little between frequencies of 50MHz and 10GHz.