柠檬酸溶胶-凝胶法制备钡铁氧体晶相变化的研究  

Crystal change of barium hexaferrite prepared by citric acid sol-gel method

作　　者：刘建武[1,2] 郭成[1] 黄海亮[2] 严生虎[2] 沈介发[2] 张跃[2] 

机构地区：[1]南京工业大学化学与分子工程学院,江苏南京211800 [2]常州大学制药与生命科学学院,江苏常州213164

出　　处：《南京工业大学学报（自然科学版）》2017年第1期26-30,共5页Journal of Nanjing Tech University(Natural Science Edition)

摘　　要：采用柠檬酸溶胶-凝胶法制得钡铁氧体磁性粉末,借助热质量分析(TGA)、红外光谱(FT-IR)、X线衍射(XRD)及扫描电镜(SEM)测试手段研究了不同柠檬酸添加量对煅烧产物晶型的影响。结果表明:当柠檬酸与金属硝酸盐摩尔配比n(CA)/n(MN)≤1.2时,钡铁氧体晶相为W型,当n(CA)/n(MN)=2时,晶相转变为M型;随着柠檬酸量的增加,燃烧产物的晶化温度升高;过量柠檬酸添加改变了中间产物Fe的存在形式,促使γ-Fe_2O_3转化为热稳定性好的α-Fe_2O_3,进而使得W型钡铁氧体的成型温度升高,出现M晶型钡铁氧体。Barium hexaferrite was synthesized by citric acid sol-gel process. The thermo gravimetric analysis （ TGA ）,Fourier transform infrared spectroscopy （ FT-IR ）, X-ray diffraction （XRD ） and scanning electron microscopy （SEM） were used to characterize the crystal phase of calcination products with different citric acid additives.Results revealed that the crystal phase of barium hexaferrite was W-type when the value of n（CA）/n（MN）≤1. 2 ,and if n（CA）/n（MN）- 2, the crystal phase would change into M- type.With the increase of citric acid,the crystallization temperature of the product would rise. The excessive citric acid additive changed the existing form of Fe,which promoted the transformation from y - Fe2O3 to a - Fe2O3,which was more stable with the increase of formation temperature of the W-type barium hexaferrite,and the appearing of M- type.

关 键 词：W型钡铁氧体 n(CA)/n(MN) Γ-FE2O3 Α-FE2O3 

分 类 号：TM277[一般工业技术—材料科学与工程]