The Study Of Electronic-Magnetic Properties Of The Rare-Earth Elements Substituted Hexgonal Ferrites

With the rapid development of modern science and technology, electromagnetic radiation on human health and all kinds of electrical and electronic equipment has the increasingly serious harm.Therefore, the development of material with good performance against EMI is of great significance.Co2Z-type hexagonal ferrite materials because of the large anisotropy field,can be used in the GHz.In the international ion substitution, formulation, preparation technology are the main research on the hexagonal ferrite materials.In this paper, I used the replacement of rare earth ions and doped SiO2 to improve the properties of Co2Z-type hexagonal ferrite material.This paper presents a study of purpose and meaning, and the limitations of currently used spinel ferrite, leds to Z-hexagonal ferrite materials which have enormous potential and displays the main research methods and research results of Co2Z– hexaferrites at home and abroad.Study the basic theory of the hexagonal ferrite and the conditions for the synthesis, structure and electromagnetic properties.First, without doping the polycrystalline Ba3Co2Fe24O41 were prepared by an usual ceramic sintering method.Study the preparation and its electromagnetic characteristics, the sintering temperature was 1200℃.Then with the replacement of REE,R = La, Gd, Ho the Ba3Co2RxFe24-xO41 was prepared, substitution X=0~0.3, and the sintering temperature was1200℃.Found that apart from La replaced, the properties of the samples were a larger improvement than without the replacement rare-earth ions.Particularly when the Gd substitution X=0.1, the samples with the following features :①high permeability;②high attrition;③high natural resonant frequency.To further enhance performance, we can improve the microstructure of materials to improve the permeability rate.Finally with the Gd replacement, different content of SiO2 were dopped.Sintering temperature was still 1200℃.When the SiO2 content of the doping was 0.2wt%, the real and imaginary parts of the permeability have been improved, the natural resonant frequency shifted to high frequency.Doped SiO2 there is not obvious impact on complex permittivity.