Abstract
Deterioration of initial permeability (μi) with frequency has been investigated with reference to chemical composition and microstructure on the MnMgZn ferrites. Gradual deterioration of μi with frequencies is serious with MnO addition on the MgZn ferrite. This is considered as a relaxation phenomenon. Relaxation time (τ) was calculated by using the relationships ω τ=1. Activation energies for MgZn and MnMgZn ferrites were 0.14eV and 0.36eV. respectively. These results indicate that the relaxation of μi for.MgZn and MnMgZn ferrites may be caused by the electron migration and cation migration, respectively.
