Preparation and microwave absorption properties of Fe-phthalocyanine oligomer/Fe3O4 hybrid microspheres

The novel nano-scale Fe-phthalocyanine oligomer/Fe₃O₄ hybrid microspheres were synthesized from bis-phthalonitrile and FeCl₃·6H₂O through a simple solvent-thermal route. The morphology and structure of the hybrid microspheres were characterized by FTIR, XRD, SEM and TEM. These results showed that the hybrids were monodispersed solid microspheres and the morphology can be adjusted by controlling the addition of bis-phthalonitrile. On the basis of these results, the formation process was discussed. Magnetization measurement indicated that saturation magnetizations decreased linearly with increasing the addition of bis-phthalonitrile, while coercivities increased. The microwave absorption properties were measured by a vector network analyzer. The dielectric loss of the hybrid microspheres was larger and a new magnetic loss peak appeared at high frequency. The microwave absorbing properties enhanced with increasing the addition of bis-phthalonitrile and a maximum reflection loss of −31.1 dB was obtained at 8.6 GHz with 1 g bis-phthalonitrile when the matching thickness was 3.0 mm. The novel hybrid materials are believed to have potential applications in the microwave absorbing performances.