Effects of Ti,Fe-doped on the Sapphire Crystals in Hydrothermal Synthesis

In this paper the effect of Fe and Ti ions on the color and shape of α Al 2O 3 crystal synthesized with hydrothermal reaction was investigated.The sapphire crystals were obtained using the hydrothermal method at lower temperature(430℃) and lower pressure (40MPa).The hexagonal prism crystal was synthesized using hydrothermal reaction without adulteration of other ions.The black crystals in the shape of hexagonal prism were obtained when FeSO 4·7H 2O were added into the reaction medium.The sapphire crystals were obtained with the addition of both FeSO 4·7H 2O and TiCl 3 into the reaction medium. The main products were the congeries of boehmite.The size of sapphire crystal was 300μm with high exponential crystal face.When FeSO 4·7H 2O and TiCl 4 were added into the reaction medium,the exposed faces of sapphire crystals are {0001},{1120},{1123} and the size of maximal twins of sapphire crystal is 200μm,the size of the least crystal is 2μm.There are a lot of congeries of boehmite in the product,and a little of needle crystal of rutile TiO 2 was observed in the product.