- 相關(guān)推薦
Regulation mechanism of EM parameters in natural ferrite and its application in microwave absorbing materials
Electromagnetic (EM) parameters (ε', ε″,μ', μ″ ) of several M2+Fe2O4 and Fe2O3 type natural ferrites with different geological occurrences are measured in this paper. The measurement results show that EM parameters of a magmatic-occurring natural ferrite is very different from other types occurring from sedimentary-metamorphic iron deposit, hydrothermal vein iron deposit, outer contact of magmatic iron deposit. It has potential to be used as magnetic absorbent in microwave absorbing materials. After mineral separation and concentration, this magmatic-occurring natural ferrite was processed into type A ferrite absorbent. Type A natural ferrite absorbent is a kind of magnetic material with low dielectric constants, high magnetic conductivity and high EM loss. Its EM parameters areε' = 58.60, ε″ = 10.0, μ' = 1.2-1.5, μ″ = 1.0-1.2, respectively. In order to illuminate the regulation mechanism of EM parameters, we studied the chemical and mineral composition of type A ferrite absorbent. There is high concentration of natural impurities, which regulate the EM parameters of type A ferrite greatly. For comparison, the other types of natural ferrite, single-phase magnetite and two-phase iron minerals (ilmenite and magnetite), have few impurity. Thus regulation mechanism of EM parameters was absent in these ferrites. As a result, the regulation of EM parameters is advantageous to develop type A natural ferrite as excellent absorbent, lowers the reflectivity coefficients and enhances the absorbing efficiency of MAM made from it. Furthermore, the impurities in type A natural ferrite and its effects on EM parameters are very difficult to simulate in the synthesize ferrite. The carbonyl-iron powder is another kind of absorbent that is used extensively in MAM. To compare the absorbing properties of these two absorbent, type A natural ferrite and carbonyl-iron powder were mixed with rubber and processed into microwave absorbing sheets with the same procedures and technics. The measurement results show that the microwave absorbing bandwidth of type A ferrite absorbent sheet material is larger than that of carbonyl-iron powder. The reflectivity coefficient is also improved in the frequency of 8-12 GHz. For the reason of low price and abundant resource, the stable performance in EM properties, type A natural ferrite absorbent is a good substitute of carbonyl-iron powder in MAM.
作 者： ZHENG Yongchun WANG Shijie FENG Junming LI Chunlai OUYANG Ziyuan LIU Jianzhong LI Xiaobiao 作者單位： ZHENG Yongchun,OUYANG Ziyuan(National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China;State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China)WANG Shijie,FENG Junming,LI Xiaobiao(State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China)
LI Chunlai,LIU Jianzhong(National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China)
刊 名： 中國科學(xué)E輯（英文版） SCI 英文刊名： SCIENCE IN CHINA SERIES E:TECHNOLOGICAL SCIENCES 年，卷(期)： 2006 49(1) 分類號(hào)： O6 關(guān)鍵詞： natural impure ferrite complex permittivity complex permeability microwave absorbing materials【Regulation mechanism of EM parameter】相關(guān)文章：
Monte Carlo EM加速算法04-26
The molecular mechanism of embryonic stem cell pluripotency maintenance04-26
氨基黑10B的EM脫色研究04-25
EM技術(shù)在水產(chǎn)養(yǎng)殖業(yè)上的應(yīng)用及發(fā)展前景04-26
EM菌活性污泥系統(tǒng)對(duì)皂素廢水的深度處理試驗(yàn)04-25
EM技術(shù)在有機(jī)污水處理方面的應(yīng)用04-26
EM用于污水灌溉對(duì)小白菜產(chǎn)量和土壤肥力的影響04-25
Preparation and mechanism of Fe3O4/Au core/shell super-paramagnetic microspheres04-26