Electromagnetic properties of Mn–Zn ferrite sintered ceramics

Abstract

Mn–Zn ferrite ceramics were prepared through the ceramic method starting from metal oxides. The ceramics’ microstructural and electromagnetic properties were then evaluated. It was found that sintering density and ferrite grain size depend on both the sintering temperature and the kinds of the raw materials used. The changes in the microstructure were responsible for variations in magnetization, permeability, and electrical resistivity. The grain boundary resistivity, evaluated from the ac resistivity analysis, was especially affected. Increases in the electrical resistivity were counteracted by increases in the magnetization and permeability. This is also reflected in a trade-off of the hysteresis loss reduction and the lowering of the eddy current loss. This relationship between microstructural and electromagnetic properties can be explained by using the nonmagnetic and insulating grain boundary model.