Chemical Vapor Synthesis and Structural Characterization of Nanocrystalline Zn_1−xCo_xO (x = 0−0.50) Particles by X-ray Diffraction and X-ray Absorption Spectroscopy

Abstract

Nanocrystalline Zn 1-x Co x O (x ) 0-0.50) particles are produced by chemical vapor synthesis using laser flash evaporation as a novel precursor delivery method. The crystal and local structure of the samples is studied using X-ray diffraction and X-ray absorption spectroscopy. A single wurtzite phase is observed in samples with cobalt contents as high as x ) 0.25 (actual content is 0.33 determined by atomic absorption spectroscopy). X-ray absorption spectra show that the Co 2+ ions are incorporated into the ZnO wurtzite lattice substituting Zn 2+ ions for cobalt contents between x ) 0.001 and x ) 0.20. Only small lattice deformations are observed in these solid solutions.

Design of Nanomaterial Synthesis by Aerosol Processes

“…Hot-wall reactors use fuel combustion or electricity to heat precursors as they flow through a ceramic or metal tube in order to evaporate solids (e.g., Zn metal for synthesis of ZnO catalysts for rubber vulcanization), to drive SiCl 4 oxidation in lightguide preform fabrication, to decompose SiH 4 for silicon synthesis (14), to decompose Ni(CO) 4 for synthesis of filamentary Ni (29), and to pyrolyze sprays of inorganic salt solutions (30) or powder mixtures by laser flash evaporation (31) for the synthesis of carbides, borides, and other materials (21). Hot-wall reactors have well-defined temperature and residence time distributions and produce approximately 10% by volume and value of commercially available aerosol-made products (2).…”

CO2‐Laser Flash Evaporation as Novel CVD Precursor Delivery System for Functional Thin Film Growth

“…In the study presented in this article, metal β ‐diketonates were used. So far, laser flash evaporation of solids has been successfully implemented as a precursor delivery method to produce nanocrystalline multinary oxide particles by chemical vapor synthesis (CVS), but to the authors' knowledge, there are no reports on thin film deposition. The method is applicable whenever functional multicomponent films and coatings with a complex stoichiometry and composition are desired.…”

Photoluminescence quenching in cobalt doped ZnO nanocrystals

“…Among the transition metals, divalent cobalt ion (Co [II]), which has an ionic radius of 0.56Å, close to 0.60Å of divalent zinc ion (Zn[II]), is known to be incorporated in ZnO nanocrystals up to 20%$30% by substituting Zn site without destroying the wurtzite structure. 4,5 This makes ZnO:Co nanocrystal an ideal platform for investigating the optical and magnetic properties of the transition metal doped nanocrystal.…”