有机凝胶先驱体转化法制备Ni-Zn-Cu铁氧体纤维

Preparation of Ni-Zn-Cu Ferrite Fibers along the Organic Gel Route

以柠檬酸和金属盐为原料,采用有机凝胶先驱体转化法制备了Ni_x-Zn_(0.8-x)-Cu_(0.2)=0.1～0.4)铁氧体纤维。通过FTIR,XRD,TG/DSC,SEM和VSM对纤维先躯体凝胶的结构、物相组成、热分解过程、热处理后产物的形貌及磁性能进行了表征。结果表明:在凝胶形成过程中金属离子单齿配位于柠檬酸根阴离子,形成线型分子结构,使凝胶有较好的可纺性;先驱体纤维经1000℃焙烧2 h可得直径约为2μm、长径比可达1000、晶粒沿轴向有序排列的Ni-Zn-Cu铁氧体纤维。这些纤维在室温下有良好的软磁特性,其磁性能与组成和热处理温度有关。所制备的有机凝胶先驱体在1200℃的热处理过程中Ni_(0.4)Zn_(0.4)Cu_(0.2)Fe_2O_4晶粒的生长呈现出低过饱和度条件下晶体台阶生长特征。

The Nix-Zn0.8x-Cu0.2（x=0.1～0.4） ferrite fibers were prepared along the organic gel route from citric acid and metal salts. The gel precursors and the products heated from the gel precursors were characterized by FTIR, XRD, SEM and TG/DSC, and the magnetic properties of the as-prepared Nix-Zn0.8-x-Cu0.2（x=0.1～0.4） ferrite fibers were measured by VSM. The gel spinnability was affected by the molecular structures of metal-carboxylate formed during the gel formation. It appears that the fibrous gel precursor consisted of linear molecules showed a good spinnability. The Ni0.4Zn0.4Cu0.2Fe2O4Fe2O4 ferrite fibers of 2 μm thick, aspect ratios of 1000 and ordered micrometer grains along the axial direction were obtained by calcination at 1000 ℃ for 2 h. Ni0.4Zn0.4Cu0.2Fe2O4 grew in setback-type at 1200 ℃ in low saturation atmosphere. The Nix-Zn0.8-xCu0.2（x=0.1～0.4） ferrite fibers showed a soft magnetism which varied with calcination temperatures and chemical composition.