【作者】 苏海林；

【导师】 娄明连； 胡国光；

【作者基本信息】 安徽大学 ， 材料物理与化学， 2003， 硕士

【摘要】 本文通过测量含有各种介质的尖晶石型铁氧体废料在7.30—11.30GHz内的微波吸收特性，研究了不同磁性与电性的介质对尖晶石型铁氧体吸波性能的影响。在此基础上，采用传统陶瓷工艺，以铁砂为原料制备尖晶石型铁氧体基复合吸波材料并通过添加适当种类的介质制得尖晶石型铁氧体基混合吸波材料，提高了尖晶石型铁氧体吸波材料的性能。同时，初步研究了磁织构化处理、双层结构及介质膜对尖晶石型铁氧体基混合吸波材料性能的影响。 实验发现：(1)不同磁性与电性的介质对尖晶石型铁氧体吸波特性的影响不同；(2)磁织构化处理对含有六角晶系铁氧体单畴颗粒的尖晶石型铁氧体基混合吸波材料的性能影响很大，可以改变匹配厚度、面密度与吸收峰峰位，提高吸收量与10dB带宽；(3)对于双层材料，层间耦合作用会影响其吸波性能，降低匹配厚度与面密度，提高吸收峰峰位。介质膜的加入则会影响层间耦合作用，减弱层间耦合作用对材料吸波性能的主导作用，提高吸收量，降低匹配厚度、面密度与10dB带宽。 通过实验，我们用铁砂等制得性能优良的尖晶石型铁氧体基混合吸波材料，其匹配厚度3.11mm，面密度0.73g／cm~2，最大吸收量30.84dB，10dB带宽3.11GHz。通过磁织构化处理，提高了其10dB带宽，使其吸收量在7.30—11.30GHz内均高于10dB。更多还原

【Abstract】 In this paper, through measuring the microwave-absorbing properties of the waste spinel ferrite which contained different magnetic and dielectric mediums in the frequency range of 7.30-11.30GHz, we studied the influence of each medium on those properties. According to the above-mentioned analyses, standard ceramic techniques were adopted to prepare spinel ferrite-based composite materials with iron-sand and the microwave-absorbing properties of spinel ferrite were improved through adding some appropriate mediums into those composite materials. In addition, we also studied the influence of magnetic texture treatment, double-layer structure and medium film on the spinel ferrite-based mixed material.The experiments showed us: firstly, mediums with different magnetic and dielectric properties had different influence on the microwave-absorbing properties of spinel ferrite; secondly, magnetic texture treatment greatly affected the microwave-absorbing properties of the spinel ferrite-based mixed material which contained single-domain particles of hexagonal ferrite, changing the matching thickness, the density of area and the position of absorption peaks and increasing the absorption quantity and the 10dB bandwidth; thirdly, the coupling effect between different layers affected the microwave-absorbing properties of the double-layer spinel ferrite-based mixed material, decreasing its matching thickness and density of area and increasing the position of absorption peaks. Moreover, the medium film affected the coupling effect, weakening its leading effect on the microwave-absorbing properties of materials, increasing the absorption quantity and decreasing the matching thickness ,the density of area and the lOdB bandwidth.After some experiments, a kind of spinel ferrite-based mixed material with fine properties was obtained. The matching thickness was about 3.11mm. The density of area was about 0.73g/cm2, The maximum absorption quantity was about 30.84dB. And the lOdB bandwidth was about 3.11 GHz. Through the magnetic texture treatment, its 1 OdB bandwidth was increased to cover the measuring frequency range of 7.30 - 11 .30GHz.更多还原