Frequency-dependent effective permeability tensor of unsaturated polycrystalline ferrites

TL;DR

This paper derives a frequency-dependent permeability tensor for unsaturated polycrystalline ferrites using an effective medium approach that accounts for domain-wall motion and domain rotation, providing insights into their magnetic behavior.

Contribution

It introduces a novel combined scattering framework to model permeability in unsaturated ferrites, integrating domain dynamics and paramagnetic states.

Findings

Computed initial permeability values.

Provided frequency spectra under varying remanent fields.

Validated the model against known magnetic behaviors.

Abstract

Frequency-dependent permeability tensor for unsaturated polycrystalline ferrites is derived through an effective medium approximation that combines both domain-wall motion and rotation of domains in a single consistent scattering framework. Thus derived permeability tensor is averaged on a distribution function of the free energy that encodes paramagnetic states for anhysteretic loops. The initial permeability is computed and frequency spectra are given by varying macroscopic remanent field.