Frequency Dependence of the Initial Permeability of Mn-Zn-Ti Ferrite with Fe-Poor Composition

Abstract

Initial permeability, permittivity and resistivity spectra of Mn-Zn-Ti ferrite with Fe-poor composition (less than 50 mol% of Fe₂O₃) (FPF) are compared with Fe-rich Mn-Zn ferrite and Ni-Zn ferrite.
Analysis of the electromagnetic characteristics shows that the skin effect and dimensional resonance can be disregarded for FPF of the measured sample size below 1 MHz.
The contribution of the domain wall and spin rotation resonance to the permeability spectra was estimated by numerical fitting of the permeability data. It was found that natural resonance occurred in FPF, as in Ni-Zn ferrite. In addition, FPF has a damping factor β smaller than the conventional Fe-rich Mn-Zn ferrite, because it does not contain Fe²⁺ ions that have non- zero orbital moment, and large magnetic anisotropy factor.