片状羰基铁/石蜡复合材料的高频磁性

High-frequency magnetic properties of carbonyl-iron particles/paraffin composite

以球形羰基铁粉为原料,在不同转速下球磨,比较了不同球磨速度下样品的形貌和静态磁性.将球磨后片状样品以50%体积浓度与石蜡均匀混合制备复合材料,利用同轴线法在0.1~18GHz频率范围内研究其复数磁导率随频率的变化.球磨后片状样品的低频磁导率实部值较未球磨样品明显增大,共振频率向高频方向移动,在1.5~16GHz频率范围内磁导率虚部值增大.将复合材料在磁场内旋转取向,可以近一步提高样品的复数磁导率,其磁导率实部值在0.1GHz时为12.1,在2GHz时为11.1,磁导率虚部最大值为6.2.可见,片状羰基铁粉复合材料是一种好的高频软磁材料.

The sphere-shaped carbonyl-iron powder is used as a raw material for ball milling to produce flake-shaped carbonyl-iron particles. The morphology and the magnetic properties of the flake-shaped particles are investigated. The frequency-dependent com-plex permeability of paraffin composites with 50% volume concentration of particles is measured using the coaxial line method in 0.1？18 GHz frequency range. The real parts of permeability of the flake-shaped composites are much higher than that of the sphere-shaped samples in the low frequency region. The resonant frequencies shift to higher frequency and the values of the imaginary permeability are increased in the range from 1.5 to 16 GHz. Furthermore, higher values of the complex permeability are obtained after the composite was oriented in an external magnetic field. The real part of permeability for the oriented com-posite is 12.1 at 0.1 GHz, and it reaches 11.1 at 2 GHz. The maximum value of the imaginary part of permeability is 6.2. This result shows that the flake-shaped carbonyl-iron particles are a good high frequency soft magnetic material.