Effect of annealing treatment on luminescence property of MgO nanowires

Magnesium oxide nanowires (NWs) were synthesized by a current heating process. The effect of annealing treatment in air on their structural and optical characteristics was investigated. As-grown NWs in diameter ranging from 30 to 70 nm and length up to several 10 μm were obtained. Carbon-coating layers were observed in the as-grown NWs which were oxidized during the annealing treatment at high temperature. Ionoluminescence spectra of the as-grown and annealed NWs have showed two emission peaks centered at 360 nm (UV emission) and 492 nm (green emission). The intensities of green emission were maximum at the annealing temperature of 650 °C for 2 h, whereas those of UV emission were decreased with increasing the annealing temperature. It is anticipated that maximum green emission correlates to the sufficient density of oxygen vacancies which was occurred by the optimum annealing parameters of both temperature and time.     

Atomic force microscopy imaging of ZnO nanodots deposited on quartz by sparking off different tip shapes

We have demonstrated a simple method for depositing ZnO nanodots on quartz substrates by sparking off different tip shapes at voltages of 2, 4 and 6 kV in air at atmospheric pressure. A comparison was made among the three tip shapes: the sharp tip, the conical tip and the dull tip. The surface morphology was then observed by atomic force microscopy. The mean height of the randomly distributed dots of approximately 8 nm was successfully deposited from the sharp tip at 6 kV. Characterizations by UV–vis spectroscopy and Raman spectroscopy have confirmed the presence of ZnO and the quality improvement by annealing treatments. Moreover, a nucleation mechanism of the nanodot formation is discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Effect of nanoporous In2O3 film fabricated on TiO2-In2O3 photoanode for photovoltaic performance via a sparking method

Journal of Solid State Electrochemistry - A simple and inexpensive sparking method was used to deposit body-centered cubic In2O3 film on TiO2 photoanode for 30–180 min for...     

A novel strongly correlated electronic thin-film laser energy/power meter based on anisotropic Seebeck effect

Strongly correlated electronic (SCE) materials including high-temperature superconducting cuprate and colossal magnetoresistance manganite thin films demonstrate tremendous anisotropic Seebeck effect which makes them very promising for developing high-performance laser detectors. In this work, laser-induced thermoelectric voltage (LITV) signals with nanosecond response time have been measured in SCE La_1?x Pb _x MnO₃ thin films based on anisotropic Seebeck effect at room temperature. The magnitude of the LITV signals increases linearly with laser energy/power density in a wide range of laser wavelengths from ultraviolet, visible to infrared based on which a novel SCE thin-film laser energy/power meter has been developed.     

Carbon encapsulated nickel nanoparticles synthesized by a modified alcohol catalytic chemical vapor deposition method

In this work, a simple and cost-efficient method was demonstrated for the production of carbon encapsulated nickel nanoparticles (CENPs). The CENPs were synthesized from nickel oxide by a modified alcohol catalytic chemical vapor deposition method at atmospheric pressure. Structural characterizations using scanning electron microscopy, transmission electron microscopy and X-ray diffraction indicated that the Ni-core mean diameter and the graphite-layer mean thickness were 98 ± 31 nm and 65 ± 35 nm, respectively. Room temperature magnetization results showed a ferromagnetic behavior of the CENPs, in which the saturation magnetization decreased with decreasing the Ni-to-C ratio whereas the coercivity increased with decreasing the Ni-core diameter.