Hydrothermal synthesis of pure BaFe12O19 hexaferrite nanoplatelets under high alkaline system

To our best knowledge, it is the first time to synthesize the single-phase BaFe12O19 hexaferrite by the single hydrothermal method at 220 °C. Meanwhile, effects of Fe/Ba ratio and KOH amount were also investigated. It was found that the proper Fe/Ba ratio could suppress the intermediate phase, such as α-Fe2O3 and BaFe2O4. One thing to be mentioned is that high alkaline system may be a key factor to prepare BaFe12O19 hexaferrite with even disk-like shape and narrow size distribution. The optimum Fe/Ba mole ratio is identified as 8:1, and the optimum dosage of KOH was 4.0 g for the preparation of single-phase BaFe12O19. Furthermore, the formation mechanism of disk-like BaFe12O19 hexaferrite was also discussed. - Highlights: ► Single-phase BaFe12O19 hexaferrite was synthesized by the single hydrothermal method. ► The only Fe/Ba mole ratio is identified as 8:1. ► The optimum amount of KOH was 4.0 g. ► Formation mechanism of disk-like shape for BaFe12O19 hexaferrite was discussed