Dielectric and Magnetic Relaxation Behavior in Fe78Si9B13/Polyaniline Composites at Radio-Frequency Range

Abstract

In this paper, Fe78Si9B13/polyaniline composites with different Fe78Si9B13 content are prepared through cryomilling and pressure molding. The dielectric and magnetic properties are investigated experimentally in the frequency range from 10 MHz to 1 GHz. Both dielectric and magnetic Debye-like relaxation behavior are observed in this frequency range. With the increase of the FeSiB content, the loss peaks in the permittivity spectrum show a redshift, but a blueshift in the permeability spectrum. The results indicate that the loss peak shift has a close relationship with the conductivity and domain wall displacement. As affected by the interface of polyaniline and Fe78Si9B13 particles, the conductivity of composites decrease with the increase of FeSiB content until the formation of 3D network of FeSiB particles, leading to the redshift of the loss peak in the permittivity spectrum. Meanwhile, the blueshift in the permeability spectrum is mainly caused by the domain wall displacement with high damping factor.