Nanocrystalline GaN has been synthesized from the solid-state reaction of GaI3 and NaN3 Using I-2 as heat sink and diluting the reactants. X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) revealed that the synthesized GaN crystallized in a hexagonal crystal structure and displayed spherical particles with an average size of 30 nm. X-ray photoelectron spectra (XPS) of the powder sample of as-prepared GaN gave the surface stoichiometry of GaN0.94. Room temperature photoluminescence (PL) spectrum showed that as-prepared GaN had one broad weak emission peak at 365 nm. The influence the addition of I-2 had on the formation of GaN was investigated, and a possible reaction mechanism was also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.