Microwave absorption properties of Ni0.6Zn0.4Fe2O4 composites with nonmagnetic nanoferrite percentages

Abstract

Microwave absorption materials need to be thin and lightweight and possess strong wave absorption ability and a wide absorption frequency band. To satisfy these conditions, we changed the microstructure of the composite by mixing ferrite material with different particle sizes. Specifically, we mixed nanosized nonmagnetic ZnFe2O4 powder into Ni0.6Zn0.4Fe2O4 powder, investigated the microwave absorption properties depending on the packing fraction. The crystal structure of the synthesized ferrite powders was analyzed through XRD, and the particle size was analyzed using a PSA and SEM. The density of the powders, which is required to measure the packing fraction, was determined via the gas disposition method, and the magnetic properties of the composites were analyzed using a VSM. The reflection loss represents the electromagnetic wave absorption characteristics, and it was calculated by substituting the measured permittivity and permeability values, into the equation based on the transmission line theory. The Ni0.6Zn0.4Fe2O4/ZnFe2O4 composite showed 99.9% absorption with a high packing fraction, and the absorption peak shifted to high frequencies. These characteristics suggest that the absorption ability and frequency range of the electromagnetic-wave-shielding composite can be easily controlled. Because of the high-absorption characteristic, absorption frequency control, and cost effectiveness, this composite can be applied to products such as thin electromagnetic-wave-shielding sheets.