Structure and optical properties of [Ba1-xY2x/3](Zr0.25Ti0.75)O-3 powders

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Synthesis and photoluminescence behavior of Bi4Ti3O12 powders obtained by the complex polymerization method

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Photoluminescent behavior of BaWO4 powders processed in microwave-hydrothermal

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(Sr,Tm)ZrO3 powders prepared by the polymeric precursor method: Synthesis, optical properties and morphological characteristics

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Intense and broad photoluminescence at room temperature in structurally disordered Ba[Zr0.25Ti0.75]O-3 powders: An experimental/theoretical correlation

Intense and broad photoluminescence (PL) emission at room temperature was observed on structurally disordered Ba[Zr0.25Ti0.75]O-3 (BZT) powders synthesized by the polymeric precursor method. BZT powders were annealed at 573 K for different times and at 973 K for 2 h in oxygen atmosphere. The single-phase cubic perovskite structure of the powder annealed at 973 K for 2 It was identified by X-ray diffraction and Fourier transform Raman techniques. PL emission increased with the increase of annealing time, which reached its maximum value in the powder annealed at 573 K for 192 h. First principles quantum mechanical calculations based on density functional theory (B3LYP level) were employed to study the electronic structure of ordered and disordered models. The theoretical calculations and experimental measurements of Ultraviolet-visible absorption spectroscopy indicate that the presence of intermediary energy levels in the band gap is favorable for the intense and broad PL emission at room temperature in disordered BZT powders. The PL behavior is probably due the existence of a charge gradient on the disordered structure, denoted by means of a charge transfer process from [TiO5]-[ZrO6] or [TiO6]-[ZrO5] clusters to [TiO6]-[ZrO6] clusters. (C) 2008 Elsevier Ltd. All rights reserved.

Ga-Modified Nanostructured ZnO: Characterization and Application in Dye-Sensitized Solar Cells

ZnO has received great attention in many applications due to its electronic and optical properties. We report on the preparation of ZnO and gallium-containing ZnO (ZnO:Ga) nanoparticles by the precipitation method. The nanoparticles have the wurtzite structure and a high crystallinity. Gallium ions are present as Ga(3+), as evidenced by the binding energies through XPS. Porosity and surface area of the powder increased under increasing gallium level, explained by the smaller particle size of ZnO:Ga samples compared with ZnO. The estimated optical band gap of ZnO was 3.2 eV, comparable to ZnO:Ga.

Structural refinement, optical and microwave dielectric properties of BaZrO3

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Effect of different surfactants on the shape, growth and photoluminescence behavior of MnWO4 crystals synthesized by the microwave-hydrothermal method

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Photocatalytic decomposition of methylene blue via Fenton mechanisms by silicon wafer doped with Au and Cu: a theoretical and experimental study

In this work, we studied the photocatalytic and the structural aspects of silicon wafers doped with Au and Cu submitted to thermal treatment. The materials were obtained by deposition of metals on Si using the sputtering method followed by fast heating method. The photocatalyst materials were characterized by synchrotron-grazing incidence X-ray fluorescence, ultraviolet-visible spectroscopy, X-ray diffraction, and assays of H(2)O(2) degradation. The doping process decreases the optical band gap of materials and the doping with Au causes structural changes. The best photocatalytic activity was found for thermally treated material doped with Au. Theoretical calculations at density functional theory level are in agreement with the experimental data.

Photoluminescence in quasi-amorphous Pb0.8X0.2Zr0.53Ti0.47O3 (X = Ca, Sr and Ba) powders: An optical and structural study

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Structural refinement, growth process, photoluminescence and photocatalytic properties of (Ba1-xPr2x/3)WO4 crystals synthesized by the coprecipitation method

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Optical and dielectric relaxor behaviour of Ba(Zr0.25Ti0.75)O-3 ceramic explained by means of distorted clusters

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Photoluminescence behavior in MgTiO3 powders with vacancy/distorted clusters and octahedral tilting

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Photoluminescence property of Ba(Zr0.25Ti0.75)O-3 powders prepared by solid state reaction and polymeric precursor method

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BaMoO(4) powders processed in domestic microwave-hydrothermal: Synthesis, characterization and photoluminescence at room temperature

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