有机凝胶先躯体转化法制备六角铁氧体中空纤维

Preparation of Hexaferrite Hollow Fibers by Organic Gel Precursor Transformation Method

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直径在0.5-3μm M型钡锶铁氧体(Ba0.5Sr0.5Fe12O19)中空纤维。通过TG/DSC、FTIR、XRD、SEM和VSM等技术对所得纤维进行了表征。结果表明,凝胶的可纺性与pH值有关,当pH值在4.5左右时,凝胶的可纺性最好。经700℃焙烧后,制备的M型钡锶铁氧体纤维具有较大的长径比和明显的中空结构,组成纤维的晶粒形貌为六角片状。随着温度的升高,晶粒片状结构越来越明显。经800℃焙烧后制备的M型钡锶铁氧体纤维在室温下的饱和磁化强度为59.5A.m2.kg-1,矫顽力为330.1 kA.m-1。

Ba0.5Sr0.5Fe12O19 hexaferrite hollow fibers with diameters of 0.5 to 3μm have been prepared by the organic gel precursor transformation method. The gel-precursor decomposition and ferrite formation were analyzed by thermo-gravimetric and differential scanning calorimetry, infrared spectroscopy, scanning electron microscopy and X-ray diffraction. The magnetic property of the Ba0.5Sr0.5Fe12O19 hexaferrite hollow fibers were characterized with vibrating sample magnetometer. The results show that the gel spinnability is related with pH value. The gel exhibits an appropriate spinning performance when the pH value is around 4.5. The Ba0.5Sr0.5Fe12O19 ferrites are formed after being calcined at 700℃ for 2 hours and these Ba0.5Sr0.5Fe12O19 ferrite fibers with a high aspect ratio are fabricated of particles with a hexagonal plate-like morphology, which grow with the calcination temperature. The Ba0.5Sr0.5Fe12O19 ferrite hollow fibers calcined at 800℃ for 2 hours exhibit the saturation magnetization of 59.5A.m2.kg-1 and the coercivity of 330.1 kA. m-1.