MICROANALYSIS OF WURTZITE-GAN SINGLE-CRYSTALS PREPARED BY DC ARC-DISCHARGE

Gallium nitride crystals with definite faces have been fabricated by d .c. are discharge using gallium and H-2 + NH3 as starting materials. T ransmission electron microscope, selected area diffraction and X-ray d iffraction investigation of the as-grown GaN crystals show that the we ll faceted crystals are single crystalline GaN having a wurtzite struc ture with lattice constants a(0) = 3.18 Angstrom and c(0) = 5.18 Angst rom. Both X-ray microanalysis and nano-probe diffraction techniques ha ve been used to determine the composition and microstructure of the sa mples.