Papers by Keyword: SnO

Abstract: We report on an approach for the in-situ synthesis (chemical method based) of SnO-SnO₂ nanocomposites followed by characterisation (including morphological, chemical, structural and optical) and investigation of the electrical properties of the nanocomposites with reference to the as-synthesized SnO₂ nanoparticles. Compared to spherical SnO₂ particles, the SnO phase is found existing in the form of sheet like morphology. It has been found that through controlling of the Sn:OH precursor ratio is effective for the achievement of SnO phase. Compared to the pristine SnO₂ nanoparticles, the current-voltage (I-V) characteristics of the nanocomposites show the p-n junction characteristics. The observation of rectification ratio 2.05 indicates the excellent rectifying property of the nanocomposites due to the presence of p-type SnO phase. Further, exploration of the I-V characteristics has revealed the dominance of space-charge limited current transport mechanism for the nanocomposites sample. The lattice defects are discovered to be the cause of the transport mechanism in the nanocomposites sample.

Abstract: Large-scale stannous oxide (SnO) nanowires were synthesized via a template and catalyst-free thermal oxidation process. After annealing Sn nanowires embedded AAO template in atmosphere, we observed a large scale of SnO nanowires. SnO nanowires were first prepared via the electrochemical deposition and an oxidization method based on an AAO template. The preparation of SnO nanowires use aluminum sheet (purity 99.999%) and then two-step anodization procedure to obtain raw alumina mold. Finally, transparent alumina mold (AAO template) were obtained by the reaming, soaking with phosphoric acid for 20 minutes and a stripping process. We get a pore size of < 20 nm transparent alumina mold. In order to electroplating needs, we produce platinum film on the bottom surface of AAO template by using sputtering method as the electrode of electroplating deposition. The structure was characterized by X-ray diffraction (XRD). High resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM) with x-ray energy dispersive spectrometer (EDS) was used to observe the morphology. The EDS spectrum showed that components of the materials are Sn and O. FE-SEM results show the synthesized SnO nanowires to have an approximate length of ~ 10 - 20 μm with a highly aspect ratio > 500. SnO nanowires with an Sn/O atomic ratio of ~ 1 : 1 were observed from EDS. The crystal structure of SnO nanowires showed that all the peaks within the spectra can be indexed to SnO with a tetragonal structure. This studies may lead to the use of the 1D structure nanowires into electronic nanodevices and/or sensors, thus leading to nanobased functional structures.

Abstract: This Borosilicate glass offers superior properties to the ordinary silicate glass. Metallic quantum dots embedded in glass are promising materials which can be used in modern optical devices. However, the introduction of metallic quantum dots into borosilicate glass has not been studied. We investigated the formation of copper quantum dots in Cu-doped borosilicate glass matrix using thermal annealing process. The reductant SnO included in borosilicate glass played an important role in the formation of the metallic quantum dots. Specifically, Cu quantum dots were formed only when SnO content reached at least 0.5 wt% after borosilicate glass was heated at 600 °C for 60min, which was evidenced by the detection of the characteristic absorption band at about 560nm originated from the surface plasmon resonance of Cu nanoparticles. The optimal concentration of SnO was found to be 1.5 wt% and the mean size for the heating-induced Cu quantum dots was calculated to be ~1.7 nm. Our data offer a simple approach to prepare the metallic quantum dots in borosilicate glass matrix and suggest a new type of metallic quantum dots for applications where superior durability, chemical and heat resistance are required.

Abstract: In this work, we present results about the preparation and characterization of stannous oxide (SnO) thin films. SnO thin films were obtained via thermal evaporation method from SnO₂ powder as source material. These thin films were successfully deposited onto well cleaned glass substrates by thermal evaporation technique. The as deposited thin films were of thickness of 2500 Å and film were post-deposition annealed in air ambient at 400°C for 20 min and 40 min, respectively in a furnace. As-deposited films are highly conductive and p type. The best p-type SnO film annealed at 400 °C for 40 min shows a resistivity of 1.05 Ω·cm and a relatively high hole concentration of 2 × 10¹⁷ cm³ at room temperature. The X-ray diffraction (XRD) patterns of annealed films exhibit a polycrystalline hexagonal wurtzite structure without preferred orientation. The scanning electron microscopy (SEM) image shows the presence of uniformly dispersed spherical in shaped SnO particles. The mean grain sizes (diameter) are calculated to be about 80 and 100 nm for the p-type SnO films prepared at 400 °C for 20 min, and 40 min, respectively. Room temperature photoluminescence (PL) spectra of the SnO film exhibit two emission bands, around the wavelength of 300 nm and 450 nm. All spectra were measured at room temperature.

Abstract: Nanometer oxides e.g. SnO2, ZnO, TiO2, ZrO2, etc. have photocatalytic and gas sensing properties which can be different in nanometer range. They have been produced by several methods such as Chemical Bath Deposition (CBD), Pulsed-laser deposition, Chemical Vapor Deposition (CVD), screen printing and firing process, spray pyrolysis technique, magnetron sputtering, mechanical alloying, etc. It was found that the production method and its parameters would affect the size and morphology of these oxides. By using a composite of these oxides their properties would also be affected. In this paper the effects of sonication and reaction temperatures on SnO/ZnO coupled oxides' morphologies were investigated. These coupled oxides were characterized by X-Ray Diffraction (XRD), X-Ray Florescence (XRF), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA). As a result of using the ultra sound source, the sizes of nano oxides decreased, which is one of the most important advantages of sonochemical synthesis in comparison with chemical bath deposition synthesis of these nano-composites.

Abstract: The aim of this investigation is to study the effect of SnO coatings on the bond strength between titanium and porcelain. The coatings were produced by sol-gel method and heat-treatment at 300°C. Once the coatings have been formed on the titanium substrates, self-made porcelain was fused. The specimens with pre-oxidation before porcelain fused were set as control group. It was shown SnO gel formed completely at 300°C and was composed by SnO and SnO2 in the form of a uniform film. The bond strength between titanium and porcelain of the specimens with SnO coatings was greater than those in control group statistically, which might prove that the coatings reduced the oxidation of titanium surface in the porcelain fusing progress. EDS result showed almost all fractures between titanium and porcelain occurred at the oxide layer. Si and Sn might attend the reaction at interface. It was concluded that the SnO coatings produced in this study can improved the titanium-porcelain bond strength.