FeNi合金W型铁氧体纳复合材料的吸波性能研究.docx

优秀毕业论文 精品参考文献资料 j匕塞交道叁堂亟 j匕塞交道叁堂亟±堂僮论室 △旦墨工曼△g! ABSTRACT ABSTRACT：W-type ferrites have been used as permanent magnets for microwave devices，for high—density magnetic recording and for bubble domain memories in the form of thin monocrystalline layers due to their relatively strong anisotropy andmoderated magnetization． Fine—particle ferrites show magnetic properties diferent from sintered materials．A wide range of chemical methods in the solution such as sot-gel，chemical coprecipitation， 四ass crystallization method have been used to obtain ultrafine mixed particles．In comparision with the classical ceramic methods，these methods have many advantages as follows：They reduce reaction temperatures；There is a finer and more homogenous granulometry in the obtained ferrites；Magnetic properties have greatly been improved under the same sintered temperatureWe have t订ed to synthesize W—type ferrite by citric acid method． We have t矗ed to synthesize W—type ferrite and Fe—Ni nanoparticle composites by citric acid method We compose W·-type ferrite and Fe-·Ni nanoparticle composites into ferrite／Fe—Ni nanoparticle composites． The samples were characterized by X-ray difraction(XRD)analys，transmission electron microscopy(TEM) The electromagnetic characteristics of te Fe，Co，Ni nanoparticles composites were measured by Agilent 8722ES microwave network analyzer in the band of2～1 8 GHz— The experimental results show that the dopants of the Fe—Ni nanoparticle composites call alter microstructures and magnetic properties of W-type Ferrites，and the effects are much greatly．The dopants of the Fe-Ni nanoparticle composites can also increast the value of旷．While the ratio of Fe．Ni nanoparticle composites and W—type ferrite is O．1．the effect is the greatest． KEYWORDS：Radar absorbing materials；W-type ferrites；Fe-Ni nanoparticle composites； Absorbing property CI．ASSNo：TB332 学位论文版权使用授权书本学位论文作者完全了解北京交通人学有关保留、使用学位论文的规定。特授权北京交 学位论文版权使用授权书 本学位论文作者完全了解北京交通人学有关保留、使用学位论文的