Dissolution and Recrystallization of GaN in Molten Na

The dissolution mass of GaN in molten Na at 650–800°C and 3–5 MPa of N 2 was determined by weight loss of polycrystalline GaN fragments immersed in Na and by chemical analysis of the amount of Ga dissolved in Na. The dissolution of GaN in Na was equilibrated within 100 h and the dissolution mass increased with increasing temperature but decreased with increasing N 2 pressure. It was found that the addition of a small amount of Li 3 N into the Na melt increased the dissolution mass of GaN. Transparent platelet single crystals of GaN with sizes over 300 µm were grown from nutrient GaN powder by cooling a Na solution with a Li 3 N additives from 800°C to 700°C at 1°C/h.