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Effect of cerium on structure,magnetism and magnetostriction of Fe_(81)Ga_(19) alloy

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Journal of Rare Earths 2018年第7期36卷 721-724页

作者： Tingdong Zhou Yu Zhang Daocheng Luan Qing Cai School of Materials Science and Engineering Xihua University

FeGa alloy is a new kind of magnetostrictive material, and rare-earth cerium can improve its magnetostrictive property.（Fe（81）Ga（19））（100-x）Cex（x = 0, 0.3 at%, 0.7 at%, 1 at%） samples were prepared by doping cerium in Fe（81）Ga（19） alloy. Their microstructures and phases were studied, and valence electronic structures were investigated. electromagnetic parameters, such as coercivity, saturation magnetization,remnant magnetization and saturation magnetostrictive coefficients（λs） of every sample were *** atoms are distributed at grain boundaries, and the Ce-doped alloys remain the A2 structure of FeGa alloy. When x is 0.7, the value of saturation magnetism is 217.08 emu/g, which is the maximum in the Ce-doped samples. The equivalent half length of single bond is the maximum also, and reaches to0.11380 nm. At the same time, the number of covalent electrons is 3.5672, and is the minimum of the Cedoped samples. Its As is the largest in the four samples. The change of As results in the change of equivalent half length of single bond in Ce-doped alloy.

关键词： FeGaCe alloy Valence electronic structure electromagnetic parameter Saturation magnetostrictive coefficient Rare-earth doping

Effect of Grinding Techniques on Absorbing Characteristics of Short Iron Fibers

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Journal of Wuhan University of Technology(Materials Science) 2007年第3期22卷 400-403页

作者：程海峰 Key Lab of Advancd Ceramic Fibers & Composites National University of Defense Technology

Microwave-absorbing properties of iron fibers can be adjusted by their aspect ratio. This paper presents several modification techniques for grinding long iron fibers to a suitable aspect ratio. The grinding instruments include pulsator, jet mill and muller. The aspect ratio distribution, microstructure, electromagnetic parameter and reflectivity of the samples were analyzed and discussed in detail. The results show that the fractions of 5〈aspect ratio〈40 for the three methods are 69.03%, 81.11% and 80.2% , respectively, that is, suitable short iron fibers can be obtained by the jet mill and muller. Furthermore, the short iron fibers milled by jet mill and muller have better absorbing propterties than those obtained by the pulsator under the same condition. Therefore, their microwave absorption properties can be improved by regulating the electromagnetic parameters with grinding.

关键词： short iron fiber electromagnetic parameter microwave-absorbing property

Synthesis and Microwave electromagnetic Properties of M-type Hexagonal FerriteBaTiCoFe_(10)O_(19)

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Journal of Wuhan University of Technology(Materials Science) 2001年第3期16卷 23-25页

作者：方亮 State Key Lab. of ATMSP Wuhan University of Technology Wuhan 430070 China

An M-type hexagonal ferrite BaTiCoFe10 O19 was prepared by solid phase reaction by a partial 2Fe3+→Ti4+ Co2+ substitution. The morphology observation and phase identification of BaTiCoFe10O19 were carried out by SEM and XRD, and its X-ray powder diffraction data was reported in this paper for the first time. Further, the microwave electromagnetic properties of BaTiCoFe10O19 were measured and discussed.

关键词： M-type hexagonal ferrite XRD Microwave electromagnetic parameter

The scale-transformation of electromagnetic theory and its applications

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Chinese Physics B 2005年第4期14卷 646-655页

作者：李应乐黄际英 Scentificresearchoffice XianyangTeacher'sCollegeXianyang712000China SchoolofScience XidianUniversityXian710071Chinab//ScentificresearchofficeXianyangTeacher'sCollegeXianyang712000China

The scale-transformation of electromagnetic theory is investigated in detail based on the form of Maxwell equations in scale-transformation being unchanged in different coordinate systems. The relations of electromagnetic parameters in a rectangular coordinate system and in a spherical coordinate system are presented respectively. The scale-transformation invariants for electromagnetic field are derived and their physical meaning is also presented. It is indicated by simulation that the electromagnetic waves located in medium can be considered to be isotropic due to the fact that the size of propagating vector affected by the scale factors and observing azimuth is on a size of 10-9, which provides a new approach for investigating the electromagnetic characteristics of ellipsoidal targets.

关键词： scale-transformation electromagnetic parameter transformation invariants electromag netic scattering