单轴-平面W型复合锶铁氧体的制备及其吸波特性研究

A study on preparation and microwave absorbing properties of the uniaxial and planar W-type composite Sr-ferrites

用草酸盐共沉淀和微量掺杂法研制六角晶系W型Ni、Zn、Co、Al多元复合锶铁氧体。通过调节Ni2 W同Co2 W的摩尔比例 ,可使该种铁氧体易磁化方向从C单轴型向垂于C轴的平面型转化。控制置换锶铁氧体中部分Fe3 + 的微量掺杂Al3 + ,可以调整 4πMs 值 ,提高磁晶各向异性场。测试分析了 5种不同含Co量的W型复合锶铁氧体粉料涂层的吸波特性 ,发现其自然共振吸收峰随Co含量增加向低频方向偏移 ,最高吸收峰可达 3 2 .8dB ,是适用于电子隐形技术的高品位的微波吸收剂。

In this paper, the preparation of the W type composite Sr ferrites has been studied experimentally by oxalate coprecipitation process and micro doing method. The ferrites contain oxides of Ni, Zn, Co, Al and so on, and belong to the hexagonal crystal system. The easy direction for magnetization of them can be changed from the C uniax type to the planar type with adjusting the mol ratios for Ni 2W to Co 2W. The anisotropic field and 4π M s also can be increased and regulated respectively by controlling Al doped that partly replaces Fe 3+ . The absorption properties for five coated films of the W type composite Sr ferrites containing different replacement of Co 2W were measured and analyzed. We found that the natural resonance absorption peak tends to the lower microwave frequency with increasing mol number of Co 2W, and that the highest peak was 32.6dB. So the type ferrite was the high quality microwave absorbent in the electric concealment technology.