Studies on Internal Friction and Curie Temperature of NiMgCuZn Spinel Ferrites for Micro-Inductor Applications

Abstract

Three series of NiMgCuZn ferrites were prepared by conventional double sintering ceramic process. The formation of single phase in these ferrites was confirmed by X-ray diffraction. A brief review of the important investigations carried out on the internal friction behaviour of NiMgCuZnFe2O4, in the temperature range 40oC to 360oC, has been reported. In the present investigation, the composite piezoelectric resonator method has been used. The effect of compositional changes of ferrites on Curie temperature and internal friction are reported. Results and discussions on the temperature variation of internal friction of the three series of NiMgCuZnFe2O4samples are discussed. In all the series studied, only single stress induced relaxation peaks are observed. These studies were carried out to develop a ferrite composition for their use as core materials for microinductor applications. The results are explained in the light of structural phase transitions.