Pulsed laser deposition of CdWO4CdWO_4 thin films

Thin $CdWO_4$ films were produced on various substrates by pulsed laser deposition. A method of producing transparent films of high structural and optical quality on MgO substrate was developed. It is based on deposition of an amorphous film from a non-stoichiometric $CdWO_4$–CdO target and a consequent crystallization of the film in oxygen atmosphere at 750 °C. The quality of the films produced was verified by x-ray diffraction, electron probe microanalysis, scanning electron microscopy, Raman and optical spectroscopy

RESOLUTION ENHANCEMENT AND DECONVOLUTION INTO VIBRONIC BANDS OF THE FLUORESCENCE AND ABSORPTION SPECTRA IN THE RED REGION OF DILUTE SOLUTIONS OF CHLOROPHYLL a IN VARIOUS SOLVENTS

— The fluorescence spectra of chlorophyll a in less than 10–6 mol dm‐3 solutions of benzene, toluene, tetrahydrofurane, EPA and ethanol were determined at both room temperature and at 77 K. Resolution enhancement using Fourier transform methods revealed the presence of vibronic bands with essentially solvent‐invariant separation between their origins; this was confirmed by the quantitative deconvolution of the spectra into Gaussian bands. It was concluded that the fluorescence is due to a single spectroscopically distinct species. The absorption spectra in the above solvents include a band absent from the fluorescence spectra which, from its position and intensity, may be identified as the longest wavelength X‐polarized electronic transition of chlorophyll a. Differences observed between the shapes of the low‐and high‐temperature absorption spectra may be attributed primarily to the narrowing of bandwidths with decreasing temperature and to intensity redistribution within the bands; the apparent increase in the integrated intensity on cooling the solutions appears to be due largely to the increase in the volume concentration of the solute as a result of solvent contraction

Transparent and conductive Sb-doped tin oxide SPM tips prepared by sol-gel method

The rapid progress in scanning probe microscopy (SPM) techniques in the last decade has induced an increasing need for manufacturing advanced SPM tips. One important case is conductive and transparent tips. For such tips, only a few techniques have been proposed. which are either expensive or have poor reproducibility. We here propose a simple and cheap sol-gel technique to prepare fibers with a suitably sharp apex so that they can be used as SPM tips. The fibers were spinned off from a high-viscosity solution of tin alkoxide and SbCl3 hydrolysed in hurnid air and baked at 520 degreesC for several hours. The radii of the resulting tips were estimated by transmission electron microscopy to be less than 50 am. The resistivity of the transparent fibers was measured using different Sb-doping (0.5-1 wt.%) of the tin oxide, The temperature dependence of the conductivity and light absorption were investigated down to liquid He temperatures

Equilibrium of Copper Matte and Silica-Saturated Iron Silicate Slags at 1300 °C and PSO2 of 0.5 atm

Experimental study on the phase equilibria between copper matte with silica-saturated iron silicate slags was conducted at 1300 °C and PSO2 = 0.5 atm. The high-temperature isothermal equilibration in silica crucibles under controlled flowing CO-CO2-SO2-Ar was followed by quenching in an ice–water mixture and direct phase composition analyses by an electron probe X-ray microanalyzer. The equilibrium compositions for matte and slag, as well as the distribution coefficients, were displayed as a function of matte grade. The data set obtained at PSO2 = 0.5 atm and the previous study at PSO2 = 0.1 atm by the authors enabled an investigation on the impacts of PSO2 as well as Al2O3 and CaO additions on phase equilibria in the multiphase copper matte smelting system. Thermodynamic calculations using MTDATA software were performed to compare the experimental results with modeling. The present results enrich the fundamental thermodynamic information for the matte/slag/tridymite/gas equilibria in the primary copper smelting process at high PSO2.Peer reviewe

Metal oxide based SPM tips prepared by sol-gel method

Up to date SNOM tips have. been prepared from SiO2 based materials using etching or locally melt fibre's stretching for tip sharpening [1,2] Usage of other metal oxides has been restricted because of the lack Of methods for obtaining the tips with suitable geometrical configuration. In our previous work we have proposed the technique for preparing transparent and electroconductive SnO2 fibres and tips by sol-gel method [3]. In the present investigation we have demonstrated that the sol-gel method provides the wide range of metal oxides to obtain SPM fibre tips. The new method of preparation enables to study tips based on oxide or oxide mixtures to create sensors with new properties for different applications. We propose some methods for preparing suitable precursors for spinning of pure and mixed TiO2, SnO2, SiO2 fibres. In those new methods the sharpening of tips is achieved in fibre drawing procedure. That is carried out at room temperature in humid atmosphere and then fibres are baked at 300-700degreesC for crystallisation of the material