Ruiting MA
材料科学技术（英文）
Nanocrystalline nickel zinc ferrite powders (NixZn1-xFe2O4, A for x=0, B for x=0.2, C for x=0.5, D for x=0.8 and E for x= 1) were synthesized by polyacrylamide gel method. X-ray diffraction (XRD), transmission electron microscopy (TEM) and wave-guide were used to characterize the composition. The XRD results show that the dried gel powders are amorphous, and the characteristic peaks of the spinel Ni0.5Zn0.5Fe2O4 appear after the gel is calcined at 400℃ for 1 h. When the calcining temperatures are 600 and 800℃, the average grain sizes are identified by TEM to be 10 and 30 nm, respectively. The NixZn1-xFe2O4 powders have both dielectric loss and magnetic loss in the frequency range of 8.2–11.0GHz. With the increase of Ni2+ ions content, the dielectric parameters (ε′) and permeability (u′) of the NixZn1-xFe2O4 powders decrease while the dielectric loss (ε"), magnetic loss (u") and the reflection loss increase.
关键词:
Nanocrystalline
,
ferrite
,
electromagnetic
张宝芹
,
于名讯
,
张伟
,
黄成亮
,
李永波
宇航材料工艺
介绍了各向异性吸波材料高频磁性能,对近年来研究较多的薄膜、纤维、片状磁性吸波材料及其研究进展进行了总结,并分析了在工程化应用中存在的问题,最后,对其发展趋势和方向进行了展望.
关键词:
各向异性
,
电磁性能
,
吸波材料
马贺
,
李宝毅
,
段玉平
,
刘顺华
,
冀志江
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2010.01.007
本文采用水热合成法,以(NH_4)_2S_2O_8作氧化剂,以MnSO_4为锰源,在不同水热反应时间下制备了不同晶体结构和形貌的二氧化锰.利用X射线粉末衍射(XRD),扫描电子显微镜(SEM)和透射电子显微镜(TEM)对产物进行成分、晶型和形貌进行分析,并通过电磁参数的测试对产物的电磁特性以及电磁波损耗机制进行讨论.结果表明,水热反应时间由1h逐渐增加到48h后,二氧化锰晶体结构由纯γ型逐渐转变为纯β型,中间产物为γ、α和β的混合体,二氧化锰的形貌也由球状经团絮状后逐渐转变为直径约为5-10nm纳米线状.复介电常数随反应时间增加而增加,复磁导率却正好相反,由此最后分析了二氧化锰的电磁波损耗机制.
关键词:
二氧化锰
,
晶体结构
,
形貌
,
电磁特性
