Infrared and Raman spectroscopy study of antimony doped barium titanate prepared from organometallic complex

Pure and antimony doped barium titanate powders were prepared by polymeric precursors method through Pechini process, which was carried out as a three-stage process from organometallic complex. Obtained powder was pressed into pellets and sintering was performed at 1300 degrees C for 8 h with heating rate of 10 degrees C min(-1). The formation of phase and crystal structure of pure and Sb-doped barium titanate was approved by XRD analysis, Raman and IR spectroscopy. The influence of Sb doping on microstructure of barium titanate ceramics was investigated by scanning electron microscopy. Therefore, the relation between grain size, structure and properties of the obtained ceramics was analyzed. Influence of Sb doping on barium titanate properties was discussed

Effect of Laser Heating on Partial Decomposition of Bi12SiO20 (BSO) Single Crystal: Raman Study

The effect of laser (532 nm line of Verdi G) heating during the Raman measurements, on partial decomposition of Bi12SiO20 single crystal, was addressed in this study. The degree of decomposition directly depends on the power density and duration of the laser treatment, which are registered by the phonon Raman spectra. After laser treatment, AFM measurements register additional small spherical islands on the surface. Analysis performed on irradiated and unirradiated samples showed significant changes in transmission spectra, X-ray diffraction (XRD) pattern, Verdet constant, magneto-optical property, and absorption coefficient. The material obtained after laser irradiation can be described as specific nanocomposite consisting of bismuth oxide and silicon oxide-based nano-objects (dimensions below 15 nm in diameter), which are arranged in a matrix of Bi12SiO20

Pb1-xMnxTe and PbTe1-xSx compounds and their optical properties

Pb1-xMnxTe crystals were obtained by the Bridgman method and PbTe1-xSx crystals were grown by the vapour–liquid–solid technique. The tructural properties of Pb1-xMnxTe (x £ 0.10) and PbTe1-xSx (x £ 0.05) were observed by X-ray powder diffraction analysis. The optical properties were studied by Raman spectroscopy as a function of temperature. Measurements on these samples of different composition gave information about the Mn and S position in the lattice (off-centering), their clustering and ordering, as well as of the influence of these processes on the crystal structure and properties. The model of phonon behaviour based on the Random Element Isodisplacement model was applied, and it was found that the phonons in PbTe1-xSx show a two-mode behaviour (each TO-LO mode pair of the end members degenerates to an impurity mode), while the Pb1-xMnxTe optical phonons have a ntermediate one-two-mode behaviour (the LO-mode frequency shifts continuously from PbTe to MnTe, while the other modes resemble the two-mode case)

Optical Properties of CuSe Thin Films - Band Gap Determination

Copper selenide thin films of three different thicknesses have been prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by UV-VIS-NIR spectroscopy and photoluminescence spectroscopy. Surface morphology was investigated by field-emission scanning electron microscopy. Copper selenide exhibits both direct and indirect transitions. The band gap for direct transition is found to be similar to 2.7 eV and that for indirect transition it is similar to 1.70 eV. Photoluminescence spectra of copper selenide thin films have also been analyzed, which show emission peaks at 530, 550, and 760 nm. The latter corresponds to indirect transition in investigated material

Optical properties of CuSe thin films - band gap determination

Copper selenide thin films of three different thicknesses have been prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by UV-VIS-NIR spectroscopy and photoluminescence spectroscopy. Surface morphology was investigated by field-emission scanning electron microscopy. Copper selenide exhibits both direct and indirect transitions. The band gap for direct transition is found to be similar to 2.7 eV and that for indirect transition it is similar to 1.70 eV. Photoluminescence spectra of copper selenide thin films have also been analyzed, which show emission peaks at 530, 550, and 760 nm. The latter corresponds to indirect transition in investigated material

Optical properties of plastically deformed copper: an ellipsometric study

In this paper the results of optical properties investigations on plastically deformed copper are presented. The optical properties of the plastically deformed copper were studied using spectroscopic ellipsometry in the ultraviolet-visible (UV-VIS) range. Chemically pure copper was deformed by applying the Equal Channel Angular Pressing (ECAP) technique. During the last decade, equal-channel angular pressing procedure was used for the fabrication of ultrafine-grained metals and alloys. The plastic deformation of metallic materials leads to the production of bulk nano-scale structures with ultrafine grains and cross-sections, which remain about equal before and after deformation. The parameters of the sample were calculated using a two-film model together with the Bruggeman effective medium approximation

Optical properties of plastically deformed copper: an ellipsometric study

In this paper the results of optical properties investigations on plastically deformed copper are presented. The optical properties of the plastically deformed copper were studied using spectroscopic ellipsometry in the ultraviolet-visible (UV-VIS) range. Chemically pure copper was deformed by applying the Equal Channel Angular Pressing (ECAP) technique. During the last decade, equal-channel angular pressing procedure was used for the fabrication of ultrafine-grained metals and alloys. The plastic deformation of metallic materials leads to the production of bulk nano-scale structures with ultrafine grains and cross-sections, which remain about equal before and after deformation. The parameters of the sample were calculated using a two-film model together with the Bruggeman effective medium approximation