W型铁氧体BaCoZnFe_(16)O_(27)的制备及吸波性能

Preparation and microwave absorbent properties of W-type BaCoZnFe_(16)O_(27) ferrite

以金属硝酸盐为原料,采用溶胶-凝胶法制备了W型BaCoZnFe16O27铁氧体。利用XRD,SEM和矢量网络分析仪对样品的结构、形貌和吸波性能进行了分析与测试。并考察了焙烧温度、焙烧时间对W型铁氧体的形成及吸波性能的影响。结果表明,当焙烧温度为1200℃、焙烧时间为2h,前驱体可全部转化为单一晶相的W型铁氧体。钴锌共掺杂致使W型BaCoZnFe16O27的磁晶各向异性场和自然共振频率发生改变,进而改善了样品在低频波段的吸波性能。单一晶相的BaCoZnFe16O27铁氧体在5.5GHz处对电磁波具有良好的吸收,最大吸收强度达-18dB,吸收大于5dB的频带带宽为1GHz。

W-type BaCoZnFe16O27 ferrite was prepared by sol-gel method with metal nitrate as raw material. The structure, surface morphology and electromagnetic parameters of the samples were characterized by XRD, SEM and vector network analyzer. Influence of calcination temperature and time on crystal structure and microwave absorbent properties was also studied. The results show that pure W-tipe ferrite was prepared from precursors at calcination temperature 1200℃for 2h. And the doping of Co-Zn could change magnetic anisotropy field and natural resonant frequency of W-type BaCoZnFe16O27 ferrite, and resultantly improves their microwave absorption in C-band（4~8GHz）. The microwave absorption peak of BaCoZnFe16O27 is 18dB at 5GHz frequency and the absorption bandwidth above 5dB is 1GHz.