有机凝胶-热分解法制备尖晶石型CoFe_2O_4纤维(英文)  

Preparation of Spinel Ferrite CoFe_2O_4 Fibres by Organic Gel-Thermal Decomposition Process

作　　者：张春野[1] 沈湘黔[1] 周建新[1] 沈绛英[1] 

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《稀有金属材料与工程》2008年第1期180-184,共5页Rare Metal Materials and Engineering

基　　金：Projects (50474038, 50674048);the National Nature Science Foundation of China

摘　　要：以金属钴盐、铁盐及柠檬酸为原料，采用有机凝胶-热分解法成功制备了尖晶石型的CoFe2O4纤维。通过红外光谱（FTIR）、X射线衍射（XRD）、热重-差热分析（TG-DSC）以及扫描电镜（SEM）等分析手段对凝胶的结构、组成、热分解过程以及热处理产物的形貌进行了表征，并分析了影响凝胶可纺性以及纤维产生缺陷的各种因素。结果表明：在pH值为5．5左右的溶液中金属离子与柠檬酸反应形成具有线性分子结构的[（C6H6O7）4CoFe2]n，由这些线性分子所组成的凝胶显示出良好的可纺性。所制备的尖晶石型CoFe2O4纤维由40～50nm大小的晶粒组成，纤维直径可小于1gm，长径比达1×10^6。通过振动样品磁强计（VSM）测得这种尖晶石型CoFe2O4纤维的饱和磁化强度和矫顽力分别为81．97A·m^2／kg和1041．47×79．6A／m。Functional spinel ferrite fibers are attractive for high-tech applications. The spinel CoFe2O4 fibres have been prepared by the organic gel-thermal decomposition process from starting materials of Co, Fe nitrate salts and citric acid. The gel spinning performance was a major factor for preparation of uniform gel fibrous precursors. It was related to the citrate-metal complex structure, and linear-type structural molecule [（C6H6O7）4CoFe2]n for the gel precursor was formed during the complexation reaction between the citric acid and metal ions at pH 5.5. As a result, the gel composed of these linear-type molecules exhibited a good spinning performance. The composition, structure of the gel precursors and products derived from thermal decomposition of these precursors were characterized by FTIR, XRD and SEM. The thermal decomposition process of the gel precursors was investigated by TG-DSC. The prepared spinel CoFe204 fibres having grain sizes of 40-50 nm possess the diameters of about 1μm, spect ratios up to 1×10^6 （length/diameter）, a saturation magnetization value of 81.97 A·m^2/kg and a coercivity value of 1041.47×79.6 A/m.

关 键 词：有机凝胶-热分解法 尖晶石型铁氧体纤维 铁酸钴 可纺性 

分 类 号：TQ343[化学工程—化纤工业]