Structural studies on synthesised gallium nitride

Gallium nitride (GaN) powder has been synthesised through reaction between metal gallium and ammonia (NI-I,) in a resistively heated quartz reactor. E xperiments have been performed for various reaction temperatures (range 900 -950 degrees C) and reaction periods (4-12 h). The optimised reaction tempe rature and period are 950 degrees C and 8 h, respectively. X-ray powder dif fraction (XRD) and scanning electron microscopy (SEM) studies have been car ried our on the synthesised GaN powder for differtnt growth conditions and the results have been correlated. XRD pattern reveals that the synthesised GaN is of a single-phase wurtzite: structure. The calculated lattice parame ter values are a = 3.186 Angstrom and e = 5.174 Angstrom. XRD pattern for t he samples prepared for the reaction period of less than 8 h exhibit GaN pe aks along with gallium oxide (Ga2O3)peaks. The change in the surface featur es with respect to the reaction period has been investigated using SEM. (C) 2000 Elsevier Science B.V. All rights reserved.