锂铁氧体纳米晶材料的制备与微波吸收性能的研究

Synthesis and Microwave Absorptive Properties of Nanocrystalline Lithium Ferrite Powders

采用聚乙二醇凝胶法制备了LiFe5O8纳米晶材料，并利用XRD、DTA、TGA、IR等手段对材料的制备过程及产物进行了表征。实验结果表明，采用聚乙二醇凝胶法制备LiFe5O8纳米晶材料，不仅可以得到平均粒径在10～20nm，单相、立方晶系的锂铁氧体纳米材料，而且反应条件温和，烧结温度低，时间短，合成方法简便易行。此外，研究了锂铁氧体纳米晶材料的微波吸收性能。

Lithium ferrite LiFe5O8 nanocrystalline powders were synthesized by polyethylene glycol-gel method (PEG). The transformations of precursor to gel and to crystalline phase were characterized by differential thermal analysis (DTA),thermogravimetric analysis (TGA) and infrared spectroscopy (IR). The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The result showed that the LiFe5O8 nanocrystalline powders prepared by PEG method were spherical,non-aggregated and of single spinal structure, with the average grain size being 10-20nm. It was also found that this synthetic process is easily controlled and the products can be obtained at a lower temperature and with shorter time. Moreover,microwave absorptive properties of lithium ferrite nanocrystalline powders were investigated.Keywrods: lithium ferrite, nanocrystalline materials, microwave absorption.