			Home About us Contact

ZnO Structures (zno + structure)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Hierarchical Shelled ZnO Structures Made of Bunched Nanowire Arrays,

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2007
P. Jiang
Abstract The size- and morphology-controlled growth of ZnO nanowire (NW) arrays is potentially of interest for the design of advanced catalysts and nanodevices. By adjusting the reaction temperature, shelled structures of ZnO made of bunched ZnO NW arrays are prepared, grown out of metallic Zn microspheres through a wet-chemical route in a closed Teflon reactor. In this process, ZnO NWs are nucleated and subsequently grown into NWs on the surfaces of the microspheres as well as in strong alkali solution under the condition of the pre-existence of zincate (ZnO22,) ions. At a higher temperature (200,°C), three different types of bunched ZnO NW or sub-micrometer rodlike (SMR) aggregates are observed. At room temperature, however, the bunched ZnO NW arrays are found only to occur on the Zn microsphere surface, while double-pyramid-shaped or rhombus-shaped ZnO particles are formed in solution. The ZnO NWs exhibit an ultrathin structure with a length of ca.,,500,nm and a diameter of ca.,10,nm. The phenomenon may be well understood by the temperature-dependent growth process involved in different nucleation sources. A growth mechanism has been proposed in which the degree of ZnO22,saturation in the reaction solution plays a key role in controlling the nucleation and growth of the ZnO NWs or SMRs as well as in oxidizing the metallic Zn microspheres. Based on this consideration, ultrathin ZnO NW cluster arrays on the Zn microspheres are successfully obtained. Raman spectroscopy and photoluminescence measurements of the ultrathin ZnO NW cluster arrays have also been performed. [source]

Structure of Ga2O3(ZnO)6: a member of the homologous series Ga2O3(ZnO)m

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2008
Yuichi Michiue
The structure of Ga2O3(ZnO)6 was determined using single-crystal X-ray diffraction techniques in the space group Cmcm. The metal ion sublattice resembles some of the Zn ions in the wurtzite ZnO structure. The oxygen ion sublattice in Ga2O3(ZnO)6 also resembles some of the O ions in ZnO. Structural relationships between Ga2O3(ZnO)6 and ZnO are discussed, illustrating the process for obtaining the centrosymmetric Ga2O3(ZnO)6 structure from the noncentrosymmetric ZnO. Structures of phases in the homologous series Ga2O3(ZnO)m are predicted on the basis of the structural data for Ga2O3(ZnO)6. The structures of even m are constructed by simply extending the structure units seen in Ga2O3(ZnO)6, while those of odd m consist of structure units which are of different types from those used for even m. [source]

Influence of solution concentration and temperature on the aqueous chemical growth of zinc oxide structures

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2008
D. Vernardou
Abstract ZnO was deposited on Corning glass using an equimolar aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine by Aqueous Chemical Growth. The morphological characteristics of the as-grown ZnO structures can be varied by adjusting the precursor solution concentration and solution temperature. An increase in the precursor solution concentration induces a modification in the ZnO morphology from sub-microrod to flower-like and microrod structures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Repeated Growing and Annealing Towards ZnO Film by Metal-Organic CVD,

CHEMICAL VAPOR DEPOSITION, Issue 7-9 2009
Chia-Cheng Wu
Abstract ZnO deposited on sapphire substrate is investigated as a function of growth temperature in the range 350,650,°C. The surface morphology of ZnO structures changes significantly with increasing growth temperature. Though ZnO crystal quality and optical property can be improved under high growth temperature, ZnO is inclined to form nanostructures. Therefore, we propose the repeated growing and annealing (RGA) growth mode as a reliable and reproducible way for the growth of ZnO film. The RGA growth mode is performed at a growth temperature of 450,°C for 8,min, an anneal temperature of 650,°C for 20,min, and repeatedly switched between growing and annealing. Meanwhile, we compare the effects of annealing under Ar, N2, and O2, and found that a low resistivity of 3.4,×,10,3,, cm and a high mobility of 85.2,cm2 V,1 s,1 can be obtained annealing under N2. [source]