Synthesis And Electromagnetic Properties Of Flake-like Fe₆₅Co₃₅/Graphene Composite Materials

Traditional magnetic and its alloy material have large saturated magnetization and strong magnetic loss.But the permeability of traditional magnetic and its alloy material great decreased with the frequency increase due to the limiting of Snoek’s limit law,there was a good way to slow down the decline which was change its microstructure.This article prepared the Fe₆₅Co₃₅ by a hydrothermal method,then we improved the electromagnetic parameters of Fe₆₅Co₃₅ to reduce the amount of Fe₆₅Co₃₅,make it have a great electromagnetic wave absorption performance.The detail research as follow:1.The influence of Fe₆₅Co₃₅ electromagnetic parameters and its reflection loss with different morphology of Fe₆₅Co₃₅ have been discussed.There were gain different morphology of Fe₆₅Co₃₅ by add different content of PEG-400 in the step of hydrothermal process.Then,we investigated the electromagnetic parameters and reflection loss of different morphology of Fe₆₅Co₃₅.As result,the size of Fe₆₅Co₃₅ decreased with the additive of PEG-400,and there appeared flake-like Fe₆₅Co₃₅ when the PEG-400 added.The change of morphology of Fe₆₅Co₃₅ have a great influence of its electromagnetic parameters.When the content of PEG-400 to 20 ml,Fe₆₅Co₃₅ had an effective absorption（<-10 dB）in the frequency of 5.76 GHz-9.68 GHz,the minimum reflection loss of Fe₆₅Co₃₅ can reach-26.26 dB in the frequency of 7.44 GHz with the thickness of 2.0 mm.2.Some graphene added with Fe₆₅Co₃₅ to form composite and make it have an excellent electromagnetic wave absorption performance with low content.We explored the influence of structure morphology,electromagnetic parameters and reflection loss of Fe₆₅Co₃₅/GN with different content of graphene.The result show that,a large of Fe₆₅Co₃₅ can’t adhesion the surface of graphene with the mass fraction of graphene was 0.5%,but graphene stacked together with the mass fraction of graphene was 2.0%.When the mass fraction of graphene was 1.0%,composite had a great impendence matching,and in the frequency of 8.4 GHz-13.2 Ghz,the composite can effective absorbing electromagnetic wave.The minimum reflectivity can reaches-27.1 dB.3.In order to enhances the permittivity of Fe₆₅Co₃₅,the phosphorus dopanted into Fe₆₅Co₃₅.In the process of hydrothermal,different content of Na2H2PO2 had added to gain different P-doped Fe₆₅Co₃₅,then we investigated the structure morphology,electromagnetic parameters and reflection loss of different P-doped Fe₆₅Co₃₅.Result indicated that the morphology of Fe₆₅Co₃₅ had changed with the additive of Na2H2PO2,and cubical Fe₆₅Co₃₅ had appeared.The size of cubical Fe₆₅Co₃₅ increased with the content of phosphorus.The phosphorus dopant enhances the permittivity of Fe₆₅Co₃₅,improved the impedance matching of materials.P-doped Fe₆₅Co₃₅ had a good reflection loss performance.For P-doped Fe₆₅Co₃₅ with the optimum addition of 0.5 g Na2H2PO2,the effective absorption bandwidth could cover 8 GHz-13.2 GHz with the thickness of 2 mm.The minimum reflection loss can reaches-34.2 dB.In this work,we first prepared Fe₆₅Co₃₅,then improved its performance by add graphene and doped phosphorus,make it have a good absorption performance with low content.Therefore,as-prepared composites provide a reference for new electromagnetic absorbing materials.