研究了柠檬酸盐溶胶-凝胶方法制备空心微珠-钡、锶、钴镍钡铁氧体复合粉体的微观形貌, 采用化学添加剂改善铁氧体的包覆性能. SEM、EDS分析表明铁氧体在空心微珠表面的包覆状态与铁氧体种类无关; 在前驱体中加入乙二醇或聚乙二醇可以使铁氧体对空心微珠的包覆更加完整、牢固致密. 用网络分析仪测试了C波段5.0～6.5GHz、X波段8.2～12.4GHz、Ku波段12.5～18.0GHz内1.8mm厚铁氧体空心微珠复合粉体制备的吸波涂层的微波损耗. 试验表明：铁氧体空心微珠复合粉体具有良好的电磁吸波性能, 吸波涂层在5～18GHz内微波反射损失总体上大于单纯铁氧体涂层; 加入乙二醇或聚乙二醇有助于提高涂层的吸波效果.

Ferrite-encapsulated cenosphere powders were prepared by citrate sol-gel method. The additive was used to improve the performance of ferrite coating. Microstructure of the products was tested by SEM and EDS. It was found that the coating was independent of the type of ferrite. Adding glycol or polyethylene glycol into the precursors can help the ferrite encapsulation. Microwave reflection loss of the coatings with thickness of 1.8mm made from ferrite-encapsulated cenosphere powders was tested in the frequency range from 5GHz to 18GHz. It was found that the ferrite-encapsulated cenosphere coating exhibited better microwave absorbing property than the pure ferrite. More, adding glycol can improve the microwave absorbing property of the coatings.