Simultaneous enhancements of remanence and (BH)max in BaFe12O19/CoFe2O4 nanocomposite powders

Homogeneous BaFe12O19/CoFe2O4 hard/soft magnetic nanocomposite powders were prepared by a one-step sol-gel method. All the nanocomposite powders show single-phase-like magnetic hysteresis loops indicating the existence of the excellent exchange spring phenomena of the hard magnetic phase and soft magnetic phase in the nanocomposite powders. The enhancements of remanence and 10% in (BH)max compared with the parent hard ferrite (BaFe12O19) can be achieved. The switching field distribution curves confirm the excellent exchange coupling between the hard and soft magnetic grains.