Ni Zn铁氧体粉末的溶胶 凝胶合成及微波性能.pdf

Ni_Zn铁氧体粉末的溶胶_凝胶合成及微波性能2
2 2
onal Univ. of Defense Technology , Changsha 410073 ,China)
Abstract :Ni Zn ferrite powder with different composition were prepared by Sol gel process using Fe (NO3 ) 3·9H2O , Ni (NO3 ) 2·
6H2O , Zn(NO3) 2·6H2O , citrate acid and ammonia as raw materials. The thermal decomposition behavior of dried gel and crystallite
size of synthesized powders were studied by using TGDTA and XRD. Moreover , the relationship of ferrite composition on electromagnetic
properties were investigated by network analyzer. The results reveal that the imaginary part of permeability of synthesized powders
decreases with frequency and the content of Zn in the Ni Zn ferrite powder.
Key words :Sol gel ;Ni Zn ferrite ;citrate acid ;microwave properties
Ni Zn 铁氧体作为电磁波吸收材料应用于 VHF/ UHF 之中。传统制备铁氧体的原料是氧化物和碳
酸盐 ,其工艺过程是混料、球磨、焙烧、再球磨 ,最后经过煅烧 ,这不仅使材料性能难以一致 ,而且在球磨
过程中将会造成氧化物颗粒表面产生缺陷和应力。目前报道的制备铁氧体粉末的方法主要有共沉淀
法、机械合金法、溶胶 - 凝胶法等[1～2 ] 。在这些方法中 ,溶胶 - 凝胶法具有原料纯度高、均匀性好、制备
温度低等特点。另一方面 ,X、Y、Z、M、W、U 型等铁氧体的微波性能有一些文献报道[3～5 ] ,而 Ni Zn 铁氧
体作为微波吸收剂具有价格便宜、易于合成等许多优点 ,最重要的是在微波频率下 ,它仍能在较宽频率