Preparation And Study Of Absorbing Properties Of Graphene/FeSiAl Composites

Electronic apparatus and communication facilities widely used in industrial,commercial and military inducing a large number of electromagnetic radiation which caused thorny problems such as electromagnetic pollution,electromagnetic interference,electromagnetic leak.Thus,to exploit an excellent absorbing materials is urgently needed.It can effectively improve the impedance matching characteristics of pure graphene by combining graphene with magnetic metal powder and possess both magnetic loss and electricity loss.It is an effective method to improve the absorbing properties.In this text,Graphene/Fe₃O₄/FeSiAl composites and graphene/FeSiAl composites were prepared by hydrothermal method and thermal decomposition method respectively.Crystal phase,microstructure,wave absorbing property of the Graphene/Fe₃O₄/FeSi Al composites and Graphene/FeSiAl composites were characterized by XRD,Raman,SEM,FTIR and VNA.The results shown that:The graphene oxide was reduced to graphene by hydrothermal reaction.And FeSiAl magnetic flakes were coated evenly by graphene and Fe₃O₄ particles.This absorbing material of flaky and granular Graphene/Fe₃O₄/FeSiAl have both magnetic loss and dielectric loss.In the frequency range of 0.2².66 GHz,when the mass ratio of graphene oxide to FeSiAl was 1:9,the minimum reflection loss of the Graphene/Fe₃O₄/FeSi Al composites was up to-17 dB at 2.56 GHz with a thickness of2 mm,and the effective absorption band?R_L<-10 dB?was 2.27².66 GHz.As the mass ratio of graphene oxide with FeSiAl increased,the effective absorption band of graphene/Fe₃O₄/FeSiAl composites moved to higher frequency,which was positive for the application of the absorbent material in the high frequency band.When graphene oxide solution was blended with FeSiAl magnetic flakes in mass concentration of0.0055 g/ml by ultrasonic dispersion method,the minimum reflection loss of the Graphene/Fe₃O₄/FeSiAl composites was up to-44.12 dB at 2.70 GHz with a thickness of 2 mm,and the effective absorption band?R_L<-10 dB?was 2.45².88 GHz.The graphene oxide reduced to graphene which were evenly coated on FeSiAl magnetic flakes by pyrolytic process.In the frequency range of 0.2².88 GHz,when the mass ratio of graphene oxide to FeSiAl was 3:7,the minimum reflection loss of the Graphene/FeSiAl composites was up to-18.73 dB at 2.66 GHz with a thickness of 2mm,and the effective absorption band?R_L<-10 dB?was 2.45².84 GHz.When graphene oxide solution was blended with FeSiAl magnetic flakes in mass concentration of 0.0055 g/ml by ultrasonic dispersion method,the minimum reflection loss of the Graphene/FeSiAl composites was up to-39.22 dB at 2.52 GHz with a thickness of 2 mm,and the effective absorption band?R_L<-10 dB?was 2.10².81GHz.