Influence of the Foaming Agent on the Particle Size and Microwave Absorption Properties of Hollow Ceramic Microspheres

In this study, based on self‐reactive quenching technique, hollow ceramic microspheres ( HCM s) containing barium ferrites were synthesized using A l+ F e ₂ O ₃ + B a O ₂ +sucrose+ epoxy resin as the reactive system and polyethylene glycol ( PEG ) as the foaming agent. The influence of PEG on the particle size and microwave absorption properties of HCM s is investigated using SEM , XRD , laser particle size analyzer and vector network analyzer. Preliminary results show that the average particle size increases initially from 28 μm to 53 μm after adding PEG , as well as the particle distribution gets narrower and the surface takes on classical hexagonal crystals. B a F e ₂ O ₄ , the intermediate phase of M ‐type barium ferrites ( B a F e ₁₂ O ₁₉ ), can be seen in XRD . The microwave absorption properties are improved greatly in the frequency range of 8–18 GH z. And the minimum reflection loss can reach −10 dB.