Greatly Enhanced Permeability and Expanded Bandwidth for Spinel Ferrite Composites With Flaky Fillers

Spinel ferrite flakes are prepared for use as fillers in electromagnetic (EM) composites. EM attenuation composites with the flaky fillers exhibit greatly enhanced high-frequency magnetic properties and attenuation properties. The complex permeability, μ'
_r,o
and μ"
_r,max
, is enhanced by above 300%, and the relative attenuation bandwidth W
_p
is increased by 40%, as compared to those for composites with conventional spherical fillers. W
_p
achieves 80% of the theoretical maximum relative bandwidth. The composites with the flaky fillers are powerful and potential candidates as EM attenuation materials with broad bandwidth at microwave frequency.