LI Lei ,YANG Xinchun , SONG Fuzhan , SHEN Xiangqian

(School of Material Science and Engineering, Jiangsu University, Zhenjiang Jiangsu 212013, China)

Abstract: Ba_0.5Sr_0.5Fe₁₂O₁₉ 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 Ba_0.5Sr_0.5Fe₁₂O₁₉ 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 Ba_0.5Sr_0.5Fe₁₂O₁₉ ferrites are formed after being calcined at 700℃ for 2 hours and theseBa_0.5Sr_0.5Fe₁₂O₁₉ ferrite fibers with a high aspect ratio are fabricated of particles with a hexagonal plate-like morphology, which grow with the calcination temperature. The Ba_0.5Sr_0.5Fe₁₂O₁₉ 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.

Key words: organic gel precursor transformation method; Ba_0.5Sr_0.5Fe₁₂O₁₉hexaferrite hollow fibers; spinnability; magnetic properties