High permeability and stress insensitivity of MgCuZn-NiCuZn ferrite composites for microinductor applications

摘要

Abstract Ferrite composites with ferrimagnetic phases (X) Ni_(0.35)Cu_(0.05)Zn_(0.6)Fe_2O_4 + (1 - X) Mg_(0.2)Cu_(0.25)Zn_(0.5) Fe_2O_4 in which X varies from 0.0 to 1.0 were prepared by conventional ceramic double sintering process. The formation of single phase spinel structure was confirmed by X-ray diffraction. Initial permeability measurements on the pure components and their composites were carried out in the temperature range 30-250 ℃. These studies show that the composites possess high initial permeability compared to the pure components. The ferrite composite with X = 0.5 showed a high initial permeability of μi = 9,619. This is explained with the help of excess properties of the solid solution. Since, the equimolar composition showed high initial permeability, (μi) stress sensitivity studies in the pure components and their equimolar composition were explored and these studies revealed that the equimolar composition exhibits a stress insensitive property. In view of the high permeability of these composites and stress insensitivity, equimolar composition of these ferrites can be exploited as core material for microinductor applications.