Composition dependences and optimization of the magnetic properties of Fe-based metallic glasses

Fe-based metallic glasses (MGs) and their derivative nanocrystalline alloys have demonstrated promising properties and found wide practical applications for soft magnetic use. Yet it still remains unclear how to improve their magnetic properties by designing the alloy compositions. Here the composition dependences of magnetic properties are systematically examined and the interdependences among these properties are elucidated for the Fe-based MGs. The mechanisms are unraveled from the concentrations of fundamental magnetic units and their exchange interactions. It is revealed that the overall soft magnetic properties can be improved by increasing the base metal content or in parallel decreasing the content of metallic alloying elements. In particular, the alloying of P is found to benefit the global properties by elevating the capacity to contain more base metals, although the exchange interactions may be weakened concomitantly. This study helps establish the composition-property correlations and outline the designing strategies to optimize the magnetic properties of Fe-based MGs. Thus it is believed to have implications for the development and applications of Fe-based amorphous and nanocrystalline alloys.