Materials Science Forum Vols. 663-665

Abstract: The porous hierarchical spherical CuInS2 microsturctures have been successfully fabricated through one-pot solvothermal technique. The crystal structure and morphology of the as-synthesized products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results reveal that the shells of CuInS2 microspheres are composed of nanosheets or nanoparticles. The possible formation mechanism of CuInS2 porous microspheres is simply discussed.

Abstract: Spin-coated films of tetra-(tert-butyl) phthalocyanine copper (CuPc(t-Bu)4) complex were obtained and characterized by Uv-vis absorption spectra and atomic force microscopy. A good linear relationship of the absorbance and solution concentration was detected. Low concentration solution could afford smooth, homogeneous and porous macrostructure film surfaces as indicated by atomic force microscopy. The responses of the film to NH3 were investigated at room temperature. In addition, the response and recovery characteristics, selectivity, stability and effect of thickness of the film to NH3 were also studied. The results indicated that the CuPc(t-Bu)4 spin-coated film could be exploited as an NH3 sensor at room temperature.

Abstract: A method for characterizing the morphology property of ZnO film surface with Gaussian correlation is investigated. The parameters of root-mean-square roughness w and lateral correlation lengthξare introduced in Gaussian model to describe the correlation properties of the random film surfaces. In the experimental performance, ZnO thin films are grown on quartz glass and silicon substrates by the reactive radio-frequency magnetron sputtering method under different deposition pressure. The surface morphologies of the film surface are scanned by an atomic force microscopy. The height auto-correlation functions and root-mean-square roughness are obtained by using the numerical calculus method. Carried on the fitting with the Gaussian function to the height auto-correlation function data, the lateral correlation lengths are extracted to describe the statistical properties of ZnO thin film in mathematics with other parameters.

Abstract: A new and facile route has been developed to synthesize β-Ni(OH)2 nanostructures using ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) as reaction media under solvothermal conditions. The β-Ni(OH)2 with different morphologies, such as nanoflakes, nanoplatelet and nanorods, can be obtained by controlling the volume ratio of the ionic liquid to water and reaction temperature. The as-prepared products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Abstract: Nickel complex [Ni(1-MeIm)6(BF4)2, 1-MeIm = 1-methylimidazole] has been prepared in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) ionic liquid by a simple solution phase method. The complex was characterized by elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared absorption spectroscopy (IR) and thermal analysis. SEM image indicates that the complex is irregular platelets with an uneven thickness in nanometer scale and variable transverse and longitudinal size, from 0.6 to 4 μm.

Abstract: Nanocrystalline silicon films have been fabricated from SiH4 diluted with H2 in very high frequency (40.68 MHz) plasma enhanced chemical vapor deposition system at low temperatures (250oC). The influence of pressure on the structural properties of nanocrystalline silicon films has been investigated. The experimental results reveal that a very high hydrogen dilution is needed to crystallize the film grown at high pressure. If the hydrogen dilution is not high enough, the film could also be crystallized through lowering the pressure. Furthermore, the crystallinity and grain size increase with decreasing the pressure. These results could be attributed to the increase of ion bombardment energy and the higher atomic hydrogen flux toward the growing film surface at lower pressures.

Abstract: For the sake of investigating the special optical character of heteronanostructures, we grow TiO2 nanowires following a three step synthesis method and coat silver nanoparticles on these nanowires with replacement method. Firstly, by adjusting the experiment parameters, we get the single crystalline titanium dioxide nanowires and control their length and diameter successfully. Secondly, we use the replacement method to make the silver nanoparticles coated on these nanowires. Finally, we use transmission electron microscopy and X-ray diffraction to characterize these productions and the results show that the silver nanoparticles are coated on the titanium dioxide nanowires uniformly and the components of these nanowires are only sliver and titanium dioxide. These new optical heteronanostructures are widely investigated all over the world and we sure that they can make great influences to the development of nanophotonics.

Abstract: Modulation transfer function (MTF) is an important parameter for one image system. In order to obtain the more imaging quality performance of the modified super-wide-angle Sagnac imaging interferometer (MSASII) put forward by our group, and also have a qualitative analysis of its advantages and disadvantages in the process of application. Its dynamic MTF is focused on in this paper. The dynamic MTF expression of the MSASII is calculated. According to earlier research parameters of the MSASII, the dynamic MTF curve is described and corresponding corrective measures in theoretical is given. The result is demonstrated that the imaging quality of MSASII could satisfy the need of detecting upper atmospheric wind field.

Abstract: A novel method for fabrication of self-supporting microbridge based on a-si films with tilted support legs for bolometer is studied in this paper. Based on the research of diffractive characteristics when the light passing through the mask in proximity lithography, we found if the distance of mask and photoresist is suitable, the intensity distribution curve of Fraunhofer diffraction (far field diffraction) at the border of contacthole is suitable to fabricate microbridge with tilted legs. By use of the method, the constant change of photoresist thickness around the contacthole can be realized using the far field diffraction proximity lithography. Then transfer the outline of photoresist to the sacrificial layer by plasma etching. Thus the fabrication of microbridge with tilted support legs was carried out easily, and this method has the advantages of low cost, simple and feasible.

Abstract: In this work, the deposits of electroless Ni-P deposits prepared by different process were studied by means of EPMA, mirohardness tester, friction-wear instrument. The experimental results showed that the microhardness of the deposits was directly affected by the phosphorus content, which was depended on the processes of electroless. The friction-wear tests showed that the Ni-P deposits composing of less phosphorus content exhibited lower friction coefficient before and after being heat treated. The conclusion was drawn that the lower phosphorus content deposits could improve the wear resistance under the condition of both as-plated and after being heat treated Ni-P deposits. The wear behavior was typical of a pure adhesive wear mechanism for the high phosphorus content deposit at as-plated and after being heat treated at 200oC. However, for the high phosphorus content deposit after being heat treated at 400oC, the alternate friction mechanisms were emerged from adhesive wear to abrasive wear with the precipitating of hard Ni3P particles during Ni-P deposits suffering friction tests