Superior electromagnetic properties of oriented silica-coated planar anisotropy carbonyl-iron particles in quasimicrowave band

For the sake of thinner electromagnetic wave absorbers used in quasimicrowave band, the composite containing planar anisotropy carbonyl-iron (PACI) coated with amorphous SiO2 particles were rotationally oriented in an external magnetic field. The oriented PACI/SiO2 particles possess higher permeability, higher permittivity and lower matching thickness (tm) in quasimicrowave band compared with the nonoriented ones. The decrease in matching thickness of the oriented composite could be well explained by the increase of μ and ε due to rotational orientation. The oriented PACI/SiO2 core–shell material exhibits great potential for application of thinner absorber in quasimicrowave frequency range.