六角晶系钡铁氧体纳米晶的制备和表征  

Synthesis and Characterization of Hexagonal Ba-ferrite Nanocrystals

作　　者：徐劲峰[1] 郭方方[1] 徐政[1] 

机构地区：[1]同济大学材料科学与工程学院,上海200092

出　　处：《同济大学学报（自然科学版）》2004年第7期929-932,938,共5页Journal of Tongji University:Natural Science

摘　　要：采用柠檬酸sol gel工艺 ,制备了Zn2 Z型 ,Zn2 W型 ,Co2 Z型 ,M型平面六角晶系的钡铁氧体钠米晶 .采用X射线衍射分析 (XRD) ,透射电镜分析 (TEM)和热分析对其物相组成、显微结构、反应过程等进行研究 ,发现采用本工艺 ,在 75 0℃的较低温度下 ,就可形成均匀单一的铁氧体纳米晶 ,并深入分析了其反应机制 ;对Zn2 Z型铁氧体的吸波特性进行了研究 ,结果表明 :在X波段 (8～ 12GHz)和Ku波段 (12～ 18GHz) ,有多个吸收峰 ,最大吸收量达 6 5dB ,10dB的带宽达到 6 .5GHz ,说明这是一种优质的宽频微波吸收材料 ,并探究了纳米吸波材料的吸波机理 .Citrate sol-gel process was used to prepare Zn 2-Z type,Zn 2-type,Co 2-type and M-type hexagonal Ba-ferrite nanocrystals.X-ray diffractometry,transmission eletron microscopy and thermal analysis were used to study the detailed information on the crystallography of the ferrite powders and the reaction process.The reaction mechanism was analyzed clearly.It was found that we could obtain uniformity and single phase Ba-ferrite nanocrystals at 750 ℃.The microwave-absorbing properties of the Zn 2-type hexagonal Ba-ferrite were studied.It is found that there are a few absorption peaks in the frequence range of X band (8～12 GHz) and Ku band (12～18 GHz),the maximal absorption quantity can reach 65 dB and 10 dB bandwidth is 7 GHz.It means the novel materials can be used to design wide-band absorbers,and the mechanism of absorbing microwave was investigated.

关 键 词：六角晶系钡铁氧体 纳米晶 柠檬酸sol-gel法 微波吸收 

分 类 号：TB383[一般工业技术—材料科学与工程]