CoFe2O4及其膨胀石墨复合物的制备与电磁性能

通过超声-共沉淀技术合成了CoFe₂O₄(CF)及CoFe₂O₄/膨胀石墨复合物(CF/EG), 并表征了样品的微观结构、形貌、热稳定性和电磁性能.结果表明, CF的磁性能受沉淀剂类型和烧结温度等因素的影响, CF/EG复合物具有良好的导电性、磁性和电磁波吸收性能.EG与CF质量比为0.8的CF/EG复合物和石蜡制成的2.0 mm涂层(质量比1:2)在13.52 GHz处的最小反射损耗为-16.08 dB, 有效带宽达6.6 GHz, 在10~18 GHz频段表现出良好的电磁波吸收性能.复合物的吸波性能主要来自于膨胀石墨的电导损耗和介电损耗、钴铁氧体的磁损耗、组分间的界面弛豫作用及协同效应.

Preparation and Electromagnetic Properties of CoFe2O4 and Its Composites with Expanded Graphite

CoFe₂O₄(CF) and the composites of CoFe₂O₄/expanded graphite(CF/EG) were prepared by ultrasound-co-precipitation method. The structures, morphologies, thermal stabilities, electrical and magnetic properties of the samples were characterized by modern measurement technology. The results indicated that the magnetic property of CF was influenced by precipitator type, sintering temperature, etc. CF/EG composites had excellent electrical conductivity and absorbing properties. The sample with 2.0 mm coating thickness, made by CF/EG composite with m(EG)/m(CF) of 0.8 and paraffin, showed a minimum reflection loss of-16.08 dB at 13.53 GHz and an available bandwidth of 6.6 GHz in the range of 10—18.0 GHz. The absorbing properties of the composites originated mainly from the conductance loss and dielectric loss of EG, the magnetic loss of CF, the interface relaxation effect and synergistic effect between the two components.