Preparation Of Spinel Ferrite-based Microwave Absorbing Materials With Iron-sand

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.