Microwave properties of nano-structured powders prepared by mechanical alloying

Mechanical alloying is a powerful tool for the fabrication of amorphous and nano-structured powder materials. Many magnetic materials fabricated by mechanical alloying have shown many unique properties. Our recent work has shown that mechanically alloyed fine nano-structured powders have the potential as microwave absorbers. In this work, we have fabricated micron and sub-micron Fe_100-xM_x with M = 3d element or 4f element. SEM, TEM, VSM and Mössbauer spectroscopy were used for powder characterization. Microwave properties were investigated using HP Vector Network Analyzer. The EM wave absorbing properties of the mechanically alloyed powders were compared with commercial Carbonyl Iron powders and pure Fe powder. Results show that mechanical alloyed Fe-based powders may be promising for microwave absorbing applications.