六角晶系BaFe_(12)O_(19)铁氧体纳米材料的表面修饰与磁性能

Magnetic Property and Surface Modification of Hexaferrite BaFe_(12)O_(19) Nanocrystalline

用溶胶-凝胶自蔓延燃烧法在700℃退火制备了六角晶系BaFe12O19铁氧体纳米材料,并采用原位合成的方法在其表面修饰了一定量的导电聚苯胺(PANI)。借助 FTIR、XRD、TEM 和 VSM 等分析手段表征了样品的形貌、结构及磁性能。结果表明,当修饰质量比为 10%、30%时,饱和磁化强度(Ms)从未修饰的 36.4 Am2/kg分别下降至 31.3 Am2/kg 和 18 Am2/kg, 而矫顽力(Hc)由未修饰的 44 kA/m 分别增大至 55.7 kA/m 和 62.8 kA/m。同时,剩磁比(Mr/Ms) 均在 0.6 左右。另外,对聚苯胺修饰前后钡铁氧体磁性能的变化以及与磁性能有关的纳米尺寸效应进行了分析讨论。

Hexaferrite BaFe12O19 nanocrystalline was prepared by sol-gel auto-combustion followed by subsequent annealing at 700℃, and was modified in-situ on the surface of BaFe12O19 nano-crystalline particles with a small amount of conductive polyaniline （PANI）. The morphology, microstructure and magnetic property were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD） and vibrating sample magnetometer （VSM）, respectively. When modifying on the surface of BaFel2Ol9 nano-particles with PANI of 10 wt% and 30 wt%, respectively, the Ms decreases from 36.4 A ·m^2/kg to 31.3 A ·m^2/kg and 18 A ·m^2/kg, whereas, the Hc increases from 44.1kA/m to 55.7kA/m and 62.8kA/m respectively, and the value of Mr/Ms for all samples is around 0.6. Additionally,the effect of nanometer size related to magnetic properties and the variation of magnetic properties after PANI modification were also discussed.