Nitrogen Doping
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. The Surface Treatment of Niobium Superconducting Reentrant Cavities by Means of High Temperature Nitrogen Plasma Based Ion Implantation
High Temperature Nitrogen Plasma Based Ion Implantation (HT-NPBII) has been used to treat the surface of niobium superconducting reentrant cavities, which are part of parametric transducers in a resonant-mass gravitational wave detector. The aim is to enhance the corresponding electrical quality factors (Q-factors) which are closely related with the increase
Mat. Res.. Publicado em: 13/12/2019
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2. Effect of thermal treatment on points defects of Al-N codoped ZnO films
ABSTRACT The effect of annealing temperature on the structural properties of Al-N codoped ZnO films were studied by X-ray diffraction, photoluminescence and Raman spectroscopy. ZnO films were deposited by sputtering technique on silicon substrates at 20 ºC, Al-concentration was kept constant and N-flow was changed to 6, 12 and 15 sccm. A thermal treatment w
Matéria (Rio J.). Publicado em: 19/07/2018
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3. Photocatalytic Activity and RNO Dye Degradation of Nitrogen-doped TiO2 Prepared by Ionothermal Synthesis
This work concerns the preparation a nitrogen-doped TiO2 by ionothermal synthesis methods and the photocatalytic studies. In this procedure, alkoxide was used as a titanium source, and a deep eutectic mixture of choline chloride and urea (molar ratio 1:2) served as a solvent and source of nitrogen. Different samples were synthesized varying the percentages o
Mat. Res.. Publicado em: 20/03/2017
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4. N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions
N-F codoped TiO2 films were immobilized on stainless steel sheets through a combined approach involving a dip-coating technique and a hydrothermal treatment, followed by calcination at 400°C in the presence of air. Photocatalyst characterization was conducted using XRD, Raman and UV-VIS spectroscopy as well as SEM. The films were tested in a three-electrode
Mat. Res.. Publicado em: 23/02/2017
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5. Conformational analysis and electronic structure of chiral carbon and carbon nitride nanotubes
Geometry and electronic structure of chiral carbon and carbon nitride (CNx) nanotubes were investigated through quantum chemical methods. Finite nanotubes with diameters ranging from 5 to 10 Å and containing up to 500 atoms were considered. CNx structures were built through random substitution of carbon atoms by nitrogen. The molecules were fully optimized
Materials Research. Publicado em: 30/09/2011
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6. Estudo da atividade fotocatalítica de nanotubos de TiO2 dopados com nitrogênio
This work presents the study of the catalytic performance of nanostructured titanium oxide, TiO2, doped with nitrogen in order to improve its photocatalytic activity under visible light. TiO2 nanotubes were prepared by hydrothermal method, where TiO2 particles react with NaOH at high temperature and pressure. Then the material was handled through an acid was
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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7. Estudo da dopagem em nanotubos de carbono por espectroscopia Raman ressonante.
Doping of single wall carbon nanotubes with boron, nitrogen, phosphorous and sulfur was studied by resonance Raman spectroscopy. The doping atoms were inserted in the tube walls during synthesis, by using chemical vapor deposition, laser ablation and arc discharge methods. The analysis of the Raman spectra shows that the insertion of dopants generates tubes
Publicado em: 2009
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8. Estudo e aplicação das propriedades elétricas, térmicas e mecânicas de materiais amorfos piezoresistivos em transdutores de pressão. / Study and application of eletrical properties, thermal and mechanical of amorphus matherials in piezoresistive.
This tesis presents the piezoresistivity theoretical and experimental study for two materials with amorphous structure. The first material is the Diamond Like Carbon and the other is the Indium Tin Oxide. The work includes the bibliographic study, theoretical and practical design of structures for testing individual and piezoresistors configured in bridge, i
Publicado em: 2009
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9. Estudo de Impurezas de Carbono em Nanoestruturas de BN
In this work, we performed an analysis of the structural and electronic stability of nanostructures of Boron Nitride (BN), such as layers, tubes and cones, when doped with Carbon, through first-principles calculations as implemented in code SIESTA. We found that substitutional doping of Carbon for either a single Boron or a single Nitrogen atom produces sign
Publicado em: 2008
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10. Estudo de filmes finos de GaAS (1-x) Nx/GaAS por espectroscopia Raman e de Fotoluminescência
The dependence of nitrogen (N) concentration on optical properties in thermally treated and as grown thin films of GaAs1−xNx, with 0, 0144 x 0, 0370, is investigated through Raman spectroscopy and Photoluminescence. Raman spectra exhibits the presence of two GaAs1−xNx characteristic modes. A systematic decrease of the longitudinal optical GaAs-ty
Publicado em: 2008
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11. Propriedades eletrônicas e estruturais de nanotubos de dióxido de titânio por primeiros princípios
In this work, we perform first-principles calculations based on the Density Functional Theory (DFT) to study structural and electronic properties of TiO2 nanotubes. Firstly, we address structural aspects. For this purpose we consider a model in which the nanotubes are obtained by rolling up layers of anatase TiO2 oriented in the (001) direction. The stabilit
Publicado em: 2007
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12. Estudos espectroscópicos de vidros sódio aluminofosfatos co-dopados com Yb3+ e Tm3+ / Spectroscopic studies of glasses sodium aluminophosphatos co-dopad with Yb3+ and Tm3+
This work presents a throughout near-infrared and visible spectroscopic characterization of two sets of Yb3+ and Tm3+ codoped sodium aluminophosphate glasses, prepared in nitrogen and ambient atmospheres. In these samples, the Yb3+ ions are employed as efficient sensitizers of 0.98 µm excitation, with subsequent energy transfer to Tm3+ ions. Results are dis
Publicado em: 2007