Characterization of plate-shaped strontium ferrite particles synthesized via co-precipitate and heat treatment in molten potassium bromide flux

Plate-shaped hexagonal strontium ferrite particles were synthesized using potassium bromide as the molten salt flux. The co-precipitate of strontium and iron hy-droxides was heated in the temperature range of 670-870 & DEG;C in the flux. Clear peaks based on hexagonal ferrite and weak peaks based on & alpha;-Fe2O3 were observed after the heat treatment at 670 & DEG;C. The peaks based on & alpha;-Fe2O3 almost disappeared after the heat treatment at 730 & DEG;C, and the peaks observed in the particles heated at temperatures higher than 730 & DEG;C were consistent with the standard data for SrFe12O19. The particle shape tended to change from a hexagonal plate shape to a rounded plate shape with increasing temperature while maintaining a particle diameter of approximately 100-200 nm. The coercive force was approximately 420-440 kA/m, while the magnetization at the applied field of 1353 kA/m was approximately 62 Am2/kg at heating temperatures higher than 750 & DEG;C.