Controllable synthesis of flake α-Al2O3 by one step method with Al(OH)3

Flake alpha-Al2O3 with large sizes and diameter-to-thickness ratios was prepared using the one step method with lowcost Al(OH)3 as the aluminum source. The effects of the mass ratio of the aluminum source to molten salt, additives, sintering temperatures, and holding times on the flake alpha-Al2O3 were studied. The size and diameter-tothickness ratios are maximized when the mass ratio is 1:2. An increased TiOSO4 content causes the size of the flake alpha-Al2O3 first to increase and then decrease, while the thickness does not change appreciably. When the Na3PO4 dosage gradually increases, the size of the flake alpha-Al2O3 first increases and then decreases, while the thickness gradually decreases. Finally, Fe2O3/alpha-Al2O3 and TiO2/alpha-Al2O3 pearlescent pigments were prepared, and TiO2/alpha-Al2O3 was applied for Raman detection. The proposed approach provides a practical method for the low-cost production of flake alpha-Al2O3 and provides suggestions for its further application.