Ultrabroad bandwidth and matching characteristics for spinel ferrite composites with flaky fillers

Abstract

Spinel ferrite flakes Ni0.97-x Znx Co0.03 Fe2 O4 with x=0.5 and 0.65 are prepared for use as fillers in electromagnetic composites. The composites with the flaky fillers exhibit greatly enhanced high-frequency and attenuation properties. The complex permeability, μ0′ and μ max ″, is enhanced by about 500%-700%, and the relative attenuation bandwidth WR is increased by 300%-440%, as compared to those for composites with conventional spherical fillers. W R achieves 90% of the theoretically maximum relative bandwidth. The composites with the spinel ferrite flaky fillers are powerful and potential candidates as electromagnetic attenuation materials with ultrabroad bandwidth at microwave L, S, and C bands. © 2010 American Institute of Physics.