Structural, magnetic and electrical properties of NiCuZn ferrites prepared by microwave sintering method suitable for MLCI applications

Polycrystalline NiCuZn soft ferrites with stoichiometric iron were prepared by a novel microwave sintering method. The powders were calcined, compacted and sintered at 950 °C for 30 min in a microwave sintering furnace. X-ray diffraction patterns confirm the formation of single phase cubic spinel structure. The grain size was estimated using SEM micrographs. The lattice constant is found to increase with increase in zinc concentration. The sintered ferrites have been investigated for their physical, magnetic and electrical properties such as bulk density, X-ray density, porosity, anisotropy constant, initial permeability, saturation magnetization, DC resistivity, dielectric constant and dielectric loss as a function of zinc concentration. Permeability, saturation magnetization, dielectric constant and dielectric loss were found to increase while DC resistivity was found to decrease with the replacement of Zn with Ni. The present series of ferrites are found to posses properties that are suitable for the core materials in multilayer chip inductors.