Development of Magnetic Materials Based on Micro-Nano Particles Natural Ferrite as Microwaves Absorber Materials

Ferrite-based magnetic materials (ferrites) can be simple iron oxide compounds such as Fe₂O₃ or Fe₃O₄, and similar compounds containing other cations besides iron, such as BiFeO₃, CaFe ₄O₇, and BaFe₁₂O₁₉. The solid phase of these compounds generally has varying magnetic properties, depending on the cation (A^+m) which is the substitution of the iron cation (Fe⁺³) in its crystal structure. In addition to the magnetic properties of interest, the compound in question also has strong absorption properties in electromagnetic waves in the frequency interval of 1-20 GHz (microwave), which is commonly used in the world of communication and radar technology. With these properties it is possible to develop these materials for electromagnetic shielding and stealth technology applications. As a magnetic element, ferrite material requires a conductive reflector element, to form a "core-shell" or "matrix-filler" system which results in absorption properties. The research that has been developed is in the form of Fe₃O₄ based micro-nano magnetic powder made from natural ferrite (iron sand). The sythesized of magnetic micro-nano particles using chemical extraction-milling and coprecipitation methods. Morphology of micro-nano particles ferrites has been confirmed by using SEM and TEM. The results of measurements of absorption of microwaves using a Vector Network Analyzer showed that the ferrite nano particle powder has greater absorption power (Reflection Loss <-20 dB) than micro particle powders with ≥ 99 % absorption in the "X-band" region. The extraction-milling method is simpler and more economical than the chemical coprecipitation method so that it is suitable to be an alternative method for producing large-scale ferrite powder.