Abstract: Hexagonal boron nitride nanocrystals were prepared by solvothermal method at 220 ℃ using Li_3N and BBr3 as raw materials. The effects of reaction time, surfactant and induced seeds on the production waere studied. The experimental results indicate that the hexagonal boron nitride was the dominant production and cubic boron nitride could be also found. The size of the crystals grew from 20 nm to 80 nm as the reaction time extended from 12 h to 36 h. With the addition of surfactant, the crystal size could be limited to 10 nm and the degree of sphericity improved. The content of hexagonal phase increased with the addition of h-AlN seeds, and some rod like h-BN nanocrystals appeared in the production.

Key words: Hexagonal boron nitride nanocrystals were prepared by solvothermal method at 220 ℃ using Li_3N and BBr3 as raw materials. The effects of reaction time, surfactant and induced seeds on the production waere studied. The experimental results indicate that the hexagonal boron nitride was the dominant production and cubic boron nitride could be also found. The size of the crystals grew from 20 nm to 80 nm as the reaction time extended from 12 h to 36 h. With the addition of surfactant, the crystal size could be limited to 10 nm and the degree of sphericity improved. The content of hexagonal phase increased with the addition of h-AlN seeds, and some rod like h-BN nanocrystals appeared in the production.