石墨烯/Fe3O4/FeSiAl复合材料的制备及吸波性能

Preparation and Absorbing Properties of Graphene/Fe3O4/FeSiAl Composites

以FeSiAl片状磁粉、膨胀石墨为主要原料,采用水热法制备石墨烯/Fe3O4/FeSiAl复合材料。通过XRD、SEM、Raman、FTIR和矢量网络分析仪（VNA）对石墨烯/Fe3O4/FeSiAl复合材料的晶相、微观形貌和吸波性能进行了表征和分析。结果表明：通过水热还原法,将氧化石墨烯还原成石墨烯,并且生成的石墨烯及Fe3O4颗粒均匀包覆在FeSiAl片状磁粉上,这种片状和颗粒状不同结构的复合,制备出了兼具磁损耗和介电损耗的吸波材料。在0.2~2.66 GHz频段内,当氧化石墨烯和FeSiAl质量比为1∶9,相应匹配厚度为2 mm时,石墨烯/Fe3O4/FeSiAl复合材料在2.56 GHz处最小反射率可达到–17 dB,其有效吸收频带范围（反射率小于–10 dB）为2.27~2.66 GHz。随着氧化石墨烯与FeSiAl质量比的增加,石墨烯/Fe3O4/FeSiAl复合材料的有效吸收频带向高频移动,有助于该吸波材料在高频段的应用。

Graphene/Fe3 O4/FeSiAl composites were prepared by hydrothermal method using FeSiAl magnetic flakes and expanded graphite as main raw materials. The crystal phase, microstructure and wave absorbing property of the obtained composites were characterized by XRD, Raman, SEM, FTIR and vector network analyzer（VNA）. The results indicated that graphene oxide was reduced to graphene by hydrothermal method. FeSiAl magnetic flakes were coated evenly by the graphene and Fe3 O4 particles. This absorbing material with both magnetic loss and dielectric loss could be realized by composite of flaky and granular. In the frequency range from 0.2 GHz to 2.66 GHz, for the graphene/Fe3 O4/FeSiAl composite prepared with a mass ratio of 1∶9（graphene oxide to FeSiAl）, the minimum reflection loss was up to –17 d B at 2.56 GHz with a thickness of 2 mm, and the effective absorption band of RL less than –10 dB was from 2.27 GHz to 2.66 GHz. Furthermore, as the mass ratio of graphene oxide to Fe SiAl increased, the effective absorption band of graphene/Fe3 O4/FeSiAl composite moved to higher frequency, which was helpful for the application of this absorbing material in high frequency band.