PVP表面修饰羰基铁/CoFe2O4核壳纳米结构的制备及低频吸波机理  

Preparation and Low Frequency Absorbing Mechanism of PVP Surface Modified Carbonyl Iron/CoFe 2O 4 Core-Shell Nanostructure

作　　者：李泽 赵芳 王建江 高海涛 LI Ze;ZHAO Fang;WANG Jianjiang;GAO Haitao(Department of Vechicle and Electrical Engineering,Army Engineering University Shijiazhuang Campus,Shijiazhuang 050003,China)

机构地区：[1]陆军工程大学石家庄校区车辆与电气工程系,石家庄050003

出　　处：《材料导报》2020年第14期14027-14033,共7页Materials Reports

基　　金：国家自然科学基金(51172282);校区科研创新发展基金(KYSZJQZL1910)。

摘　　要：采用聚乙烯吡咯烷酮(PVP)表面处理羰基铁粉,并将Co^2+与Fe^3+通过共沉淀技术直接在羰基铁颗粒表面合成CoFe2O4,成功制备了三种不同CoFe2O4含量的羰基铁/CoFe2O4核壳结构粉体。采用扫描电镜(SEM)、X射线衍射仪(XRD)、红外光谱仪(FTIR)及矢量网络分析仪(VNA)等设备分析了加入CoFe2O4前后羰基铁颗粒的形态、组成与电磁性能。结果表明,制备的纳米CoFe2O4粉末呈不规则团聚状,CoFe2O4大部分包覆于片状羰基铁表面,且随着CoFe2O4合成量的增加,包覆层厚度逐渐增大并趋于完全包覆。通过CoFe2O4粉末包覆有效降低了羰基铁的介电常数,提高了其低频波段的阻抗匹配特性,实现了铁电和铁磁双性复合吸波效果,改善了其低频吸波性能。利用λ/4干涉相消理论对反射损耗峰频率与电磁参数间的关系进行了研究,并结合界面反射模型及阻抗匹配原理对材料吸波性能进行了分析。The surface of carbonyl iron powder was treated with polyvinylpyrrolidone(PVP),and CoFe2O4 was directly synthesized on the surface of carbonyl iron particles by Co 2+and Fe^3+.Three kinds of carbonyl iron/CoFe2O4 core-shells structural powder with different CoFe2O4 content were successfully prepared.The morphology,composition and electromagnetic properties of carbonyl iron particles before and after the addition of CoFe2O4 were analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD),infrared spectroscopy(FTIR)and vector network analyzer(VNA).The results show that the irregular particle nano CoFe2O4 powder was successfully prepared.The CoFe2O4 powder was mostly coated on the surface of flaky carbonyl iron.With the increase of the amount of CoFe2O4,the thickness of the coating gradually increases and tends to be completely coated.The CoFe2O4 powder coating layer effectively reduced the dielectric constant of carbonyl iron,improved the impedance matching performance in low frequency,realized the combined absorbing effect of ferroelectric and ferromagnetic,and improved the low frequency absorbing performance.The absorbing properties of the material were analyzed by the interface reflection model and impedance matching principle.The relationship between the peak frequency of the reflection and the electromagnetic parameters was analyzed by the 1/4 wavelength interference cancellation theory.

关 键 词：羰基铁 COFE2O4 低频 吸波机理 磁性材料 

分 类 号：TB34[一般工业技术—材料科学与工程]