Preparation and microwave absorbent properties of nano-ferrite composites

Nano-ferrite composites were synthesized by sol-gel method and SHS. Crystal structure and surface appearance of products were investigated by XRD and SEM. Mass extinction coefficients of composites were more than 101 m²/g in the IR range by smoke box. Electromagnetic parameters were measured by vector network analysis from 2 GHz-18 GHz. The curve that tangent of loss angle change with frequency was drawn. The results showed that when super-fine carbon material was added into nano-ferrite, the dielectric loss was enhanced, and so electromagnetic loss was increased. It was proved that nano-ferrite composite should be acted as broad-band microwave absorbers. An approach was offered to broaden frequencies of stealth materials.