The Electromagnetic Wave Absorption Characteristics Of High-frequency Soft Magunetic Materials Of New Composite Structures

With the rising of the third technological revolution,electronic equipment has become part of our life.At the same time,electromagnetic interference and electromagnetic radiation have been become a new problem in industry.new electromagnetic absorption materials have attracted more and more attention.high frequency soft magnetic materials as electromagnetic absorption materials at room temperature are the first choice to achieve"more thinner,more lighter,more wider and more stronger".Among many high frequency soft magnetic materials,alloy materials have higher saturation magnetization and Curie temperature than ferrite materials,therefore,alloy materials has been become the hotspot as the electromagnetic absorption materials.rare-earth transition-metal(R-T)compounds as the one of alloy material have attracted much attention due to their excellent intrinsic magnetism,higher using temperature and adjustable anisotropy.In this paper,the rare-earth transition-metal(R-T)compounds is used as the matrix and the Ni-Zn ferrite was used as the additive to achieve high electromagnetic absorption performance in high frequency.Ni-Zn ferrite was prepared by solid-phase method,rare-earth transition-metal(R-T)compounds was prepared by Magnequench,and then two materials was mixed in certain proportion by using V blender mixer.Finally The absorbing material was prepared by mixing the powder with paraffin and named as FMAP.The reference group is rare-earth transition-metal(R-T)compounds-paraffin absorbing material named as AP.SEM showed that the difference between the rare-earth transition-metal(R-T)compounds and ferrite particles after ball milling.The rare-earth transition-metal(R-T)compounds and ferrite particles were flaky shape and nearly spherical,respectively.The particle size of the rare-earth transition-metal(R-T)compounds is 3-4?m,and the ferrite particle is 1-2?m.The electromagnetic parameters of the materials have been tested,we found that the permittivity of the YFe_8.5Ni_0.2Cr_0.1B_0.2-ferrite-paraffin absorption materials was lower than YFe_8.5Ni_0.2Cr_0.1B_0.2-paraffin absorption materials and more regular than YFe_8.5Ni_0.2Cr_0.1B_0.2-paraffin absorption materials,which is conductive to better impedance matching.The reflection loss curve of the material has been calculated,the curve showed that the absorption performance of the YFe_8.5Ni_0.2Cr_0.1B_0.2-ferrite-paraffin absorption materials was better than YFe_8.5Ni_0.2Cr_0.1B_0.2-paraffin absorption materials when the ratio of paraffin/absorbent increases.When the ratio of paraffin/absorbent is 1:4,the maximum absorption peak is-58 d B.-10 d B absorption bandwidth is 4.2 GHz,The best absorption matching thickness is 2.4 mm.