纳米钴、镍铁氧体的制备与吸波性能

Preparation and Microwave Absorbing Property of Cobalt and Nickel Ferrite Nanopowders

采用柠檬酸盐溶胶-凝胶法制备纳米钴、镍铁氧体。采用X射线衍射(XRD)、原子力显微镜(AFM)分析了铁氧体物相组成及微观形貌;用振动样品磁强计测定产物磁滞回线。以苯丙乳液为基相制备铁氧体涂层,用网络分析仪测试了涂层的吸波性能。结果表明,凝胶缓慢升温至850℃处理,得到结晶度良好的尖晶石型纳米钴、镍铁氧体,钴铁氧体平均粒径为36nm,镍铁氧体平均粒径为56nm。在5GHz～12GHz频段内,涂层的微波反射损耗大部分在10dB以上,具有良好的吸波性能。

The citrate sol-gel synthesis method was used to prepare CoFe2O4 and NiFe2O4 ferrite nanoparticles. The crystal phase, grain size, magnetic property of the samples were characterized by X-ray diffraction, AFM, vibrating sample magnetometer, respectively. Ferrite coatings were formed using styrene-acrylate latex as matrix, and their wave absorption were tested using network analyzer. The result showed that the ferrite nanopowders were prepared by heating the gel at 850℃, with the average grain size of CoFe2O4 NiFe2O4 ferrite of 36 nm, 56 rim, respectively. The saturation magnetization and coercivity of NiFe2O4 ferrite were a little higher than that of CoFe2O4 ferrite. Microwave absorber coatings of CoFe2O4 and NiFe2O4 were made with latex matrix and the reflection loss were more than 10dB in frequency C-band. In the frequency range of 5GHz to 12GHz, the microwave absorption of the NiFe2O4 coating was better than that of CoFe2O4 coating.