Influence of microstructure and magnetizing mechanisms on magnetic complex permeability (imaginary part) of a Cu-doped Ni-Zn polycrystalline ferrite

Abstract

The complex permeability of the Cu-doped Ni–Zn polycrystalline ferrites is strongly dependent on microstructure, particularly on relative density (ϕ) and average grain size (G), as it has been shown in a previous study developed at a constant angular frequency (107 Hz). In this study, the previous microstructural model proposed has been extended to an angular frequency range (from 106 to 109 Hz) demonstrating its validity and reliability. In addition, domain-wall motion and spin rotation contributions to magnetic permeability have been individually considered in the mathematical model, highlighting the relative influence of each magnetizing mechanism at different angular frequencies.