Magnetic properties and air stability of BaFe12O19/Fe5C2 composites fabricated through cryogenic ball milling

The BaFe12O19 particles were synthesized by co-precipitation and calcination. Fe5C2 nanoparticles were synthesized in an organic solvent. The BaFe12O19 and Fe5C2 particles were mixed through cryogenic ball milling. The elemental mappings indicated that two crystal phases were homogenously mixed after the milling, and the magnetic properties of BaFe12O19/Fe5C2 composites were investigated by VSM. When the mass percentage of Fe5C2 was 10%, the composite presented the optimum magnetic exchange coupling in BaFe12O19/Fe5C2 composites and the largest (BH)(max) (31% increase from pure BaFe12O19). As a comparison, the room temperature ball milled BaFe12O19/Fe5C2 showed less exchange coupling compared with cryogenic ball milling counterpart. Finally, the air stability of BaFe12O19/Fe5C2 composite was also investigated.