Papers by Keyword: Chemical Preparation

Abstract: Surfactant assisted synthetic route was followed to prepare silver selenide (β-Ag₂Se) nanoparticles. The effect of three different surfactants viz., Triton X100, SDS and CTAB in the formation of silver selenide nanoparticles had been examined. Pure and crystalline β-Ag₂Se nanophase was obtained in the presence of Triton X100 and SDS. However, the presence of CTAB leads to metallic silver formation. Nano Composite of β-Ag₂Se and ZnS was fabricated in the presence of glycine as a molecular linker. The products were characterized by different techniques such as XRD, FT-IR, SEM and TEM. Room temperature photoluminescence spectrum of the ZnS/ β-Ag₂Se nanocomposite exhibited two emission peaks at around 286 nm and 392 nm with enhanced intensity (l_ex = 250 nm).

Abstract: Zirconia nanopowders stabilised with 6 mol% calcium oxide were crystallised under hydrothermal conditions. The effect of pH on chemical composition, phase composition and morphology of the resultant nanopowders was studied. Behaviour of the nanopowders during uniaxial pressing and pressureless sintering was characterized. It was found that the solution pH higher than 10 is required to retain CaO totally in the nanopowder during hydrothermal crystallisation. Oval nanocrystallites of tetragonal symmetry were obtained as the main phase. An increase of the solution pH increased both the content and aspect ratio of needle-shaped crystallites of monoclinic symmetry being the secondary phase. This improved compressibility of the nanopowders but deteriorated their sinterability and the phase composition of the resultant polycrystals.