Polyaniline containing W-type hexaferrite composites for microwave absorption in high-frequency applications

The W-type hexaferrite Ba 0.85 La 0.15 Co 2 Fe 16 O 27 composite with polyaniline was synthesized by a facile route of in-situ chemical oxidative polymerization. This novel organic–inorganic composite material (PANI/Ba 0.85 La 0.15 Co 2 Fe 16 O 27 ) can be used as a potential microwave absorber. And their microstructure, static magnetization, complex permittivity, permeability and microwave absorbing properties were subsequently investigated. Compared with pure W-type hexagonal ferrite, the composites have higher permittivity and reflection loss, which gradually increase with the increase of PANI content. The excellent microwave absorption in our experiment reached to −14.95 dB at 9.3 GHz with the layer thickness of 4 mm when the mass ratio was 0.7/0.5. More importantly, well reflection loss over a wide frequency range can be achieved by manipulating the content of PANI. The results indicated that the novel organic–inorganic materials composed of polyaniline and W-type hexagonal ferrite had an excellent microwave absorption property, and may be used as lightweight and highly effective microwave absorbers.