Iron phthalocyanine oligomer/Fe3O4 hybrid microspheres and their microwave absorption property

The novel nano-scale iron phthalocyanine oligomer/Fe₃O₄ (FePc/Fe₃O₄) hybrid microspheres were synthesized from iron phthalocyanine oligomer and FeCl₃·6H₂O via a solvent-thermal crystallization route. The morphology and structure of the hybrid microspheres were characterized by Fourier transform infrared spectrophotometer, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. These results showed that the hybrids were monodisperse microspheres and the morphology can be adjusted by controlling pre-polymerization time. The saturation magnetization increased with increase in the pre-polymerization time, while the coercivities decreased. The FePc/Fe₃O₄ hybrid microspheres exhibited novel microwave electromagnetic properties: the dielectric loss was enhanced when the pre-polymerization time increased and a new microwave loss peak appeared at high frequency. The microwave absorbing properties enhanced with increase in the pre-polymerization time and a maximum reflection loss of −29.7 dB was obtained at 11.7 GHz with 6 h of pre-polymerization time when the matching thickness was 3.0 mm. The novel hybrid materials are believed to have potential applications as microwave absorbing materials.