热处理对锶铁氧体微结构及吸波性能的影响

采用溶胶凝胶自燃烧法,在不同煅烧温度条件下制备了六角锶铁氧体粉体,对其结构、形貌和电磁参数进行了分析。通过绘制匹配解析图,求得各锶铁氧体所得涂层的最佳匹配厚度和最佳匹配频率,并利用传输线理论计算了最佳条件下样品的吸波效果。结果表明:热处理温度对锶铁氧体的结构和形貌有很大影响,以5℃/min升温时,随着煅烧温度升高,颗粒由米粒状逐步转化为完美的六角片状;热处理温度对锶铁氧体吸波性能的影响也较大,1 000℃的样品吸波效果最好,当匹配厚度为5.2mm时,低于-5dB的带宽为4.5GHz,最大吸收峰值为-38dB。

Influence of Heat-treatment on the Microstructure and Microwave Absorbing Properties of SrFe12O19

M-type strontium ferrite powders were prepared by sol-gel-autocombustion and the micro-structures,morphology and the electromagnetic properties of powders were characterized.Impedance matching solution maps was designed to obtain the matching frequency and the matching thickness.Based on the match-ing frequency and the matching thickness,microwave absorption of the material was studied.The results show that with increasing of temperature the shape of particles change from rice-like to hexagon.It is found that an-nealing temperatures could affect the microwave absorbing properties of SrFe12O19.When annealing tempera-ture is 1 000 ℃ with a 5.2 mm thickness,the maximum reflection loss becomes-38 dB at 6 GHz,and the-5 dB bandwidth reaches 4.5 GHz.