Papers by Keyword: Wurtzite Structure

Abstract: ZnO nanorods have been successfully synthesized by employing ZnCl2, NaOH as the starting materials without surfactants, template supporting and structure-directing solvent at a low temperature (room temperature – 90 °C ). X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) were used to analyze the crystal structure and surface morphology. XRD pattern analysis showed that the ZnO clusters are single hexagonal phase of wurtzite structure with no impurity of others. Also, TEM images revealed that the size of a single ZnO nanorod is between 32 – 60 nm in diameter and 470 – 740 nm in length. Furthermore, the ZnO nanorods exhibit significant optical properties in Raman spectrum, suggesting that they could be found promising potential for opto-electronic application.

Abstract: In this work, ZnO nanorods have been successfully synthesized by employing ZnCl2, NaOH as the starting materials by using different surfactants (including CTAB, SDS and SDBS), without using template supporting and structure-directing solvent at a low temperature ( 60 up to 90 °C ). X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) were used to analyze the crystal structure and surface morphology. XRD pattern analysis showed that the ZnO clusters are single hexagonal phase of wurtzite structure with no impurity of others. Also, TEM images revealed that the size of a single ZnO nanorod is between 20 nm and 40 nm in diameter and between 200 nm and 2 μm in length. The structures, growth mechanism and the PL spectra properties of ZnO microcrystals are investigated.

Abstract: In this work, the structural and magnetic properties of polycrystalline Zn1-xCoxO (x = 0, 0.02, 0.05, 0.0625, 0.10 and 0.15) oxides were studied in detail. Rietveld refinement of x-ray diffraction spectra indicates that a single-phase wurtzite structure was formed in Zn1-xCoxO samples for x up to 0.10. The magnetization for x = 0.02 can be fitted to a model with a paramagnetic Curie term and a diamagnetic constant which could arise from spins of isolated free Co ions and a diamagnetic background, respectively. For x > 0.02, however, an additional antiferromagnetic Curie-Weiss term needs to employ for fitting. This is due to an additional contribution from clustered Co ions that are in nearest neighbor positions through oxygen ions. Results show that the substitution of Co at the Zn site does not occur in a completely random manner but Co ions appear to have a tendency for clustering. In addition, the homogenous ZnO:Co thin film prepared by Pulsed Laser Deposition on SiO2/Si substrate shows ferromagnetic behavior at room temperature.