Abstract
Nanocrystalline ZnO of various shapes was obtained without the use of catalysts by dry oxidation of metallic zinc. Oxidation treatments performed below the melting point of Zn (T-m = 419 degrees C) led to the formation of flakes-type structure. At 500 degrees C, long nanofibers of circular and uniform cross section covering the surface of the oxidized samples were observed. At 600 degrees C, large density of cone-shape needles covered the oxidized surface. High quality nanocrystals of hexagonal shape were obtained by vapor deposition on Pt substrate. XRD results showed that the lattice parameters of the needles are 1% smaller than those of microcrystalline ZnO.