Navegação Ciências Exatas e da Terra por Assunto "Compostos de silício"
Resultados 1-20 de 29
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Aging effects on the nucleation of Pb nanoparticles in silica
(2011) [Artigo de periódico]The ion beam synthesis of Pb nanoparticles (NPs) in silica is studied in terms of a two step thermal annealing process consisting of a low temperature long time aging treatment followed by a high temperature short time ... -
Analysis of dip coating processing parameters by double optical monitoring
(2008) [Artigo de periódico]Double optical monitoring is applied to determine the influence of main process parameters on the formation of sulfated zirconia and self-assembled mesoporous silica solgel films by dip coating. In addition, we analyze, ... -
Cluster coarsening and luminescence emission intensity of Ge nanoclusters in SiO/sub 2/ layers
(2003) [Artigo de periódico]SiO2 layers 180 nm thick are implanted with 120 keV Ge+ ions at a fluence of 1.2x1016 cm-². The distribution and coarsening evolution of Ge nanoclusters are characterized by Rutherford backscattering spectrometry and ... -
Direct etching of SiO2 and Al2O3 by 900-keV gold ions
(2009) [Artigo de periódico]We report the direct etching of Al2O3 and SiO2 using 900-keV Au+ ions. 2000-mesh Cu grids were employed as masks using two different configurations: 1 the Cu mesh was placed on top of each insulator separately and independent ... -
Effect of annealing atmosphere on the structure and luminescence of Sn-implanted SiO/sub 2/ layers
(2005) [Artigo de periódico]Sn nanoclusters are synthesized in 180 nm SiO2 layers after ion implantation and heat treatment. Annealings in N2 ambient at high temperatures sTù700 °Cd lead to the formation of Sn nanoclusters of different sizes in ... -
Electroluminescence induced by Ge nanocrystals obtained by hot ion implantation into SiO2
(2009) [Artigo de periódico]Commonly, electroluminescence (EL) from Ge nanocrystals (Ge NCs) has been obtained by room temperature (RT) Ge implantation into a SiO2 matrix followed by a high temperature anneal. In the present work, we have used a novel ... -
Enhanced hydrogen bonding stregth observed in hydrogenated SiC and SiO2/SiC structures
(2007) [Artigo de periódico]Thermally induced H incorporation, depth distribution, and loss in SiC and in thermally grown SiO2 films on SiC were investigated using isotopic substitution and nuclear reaction analyses. Hydrogen deuterium is found near ... -
Environment of hafnium and silicon in Hf-based dielectric films : an atomistic study by x-ray absorption spectroscopy and x-ray diffraction
(2005) [Artigo de periódico]The atomic structure of HfSiO and HfSiON was investigated before and after thermal annealing using x-ray diffraction and x-ray absorption spectroscopy. In HfSiO, the Hf atoms are arranged in a monoclinic HfO2 structure ... -
Experimental energy straggling of protons in SiO/sub 2/
(2003) [Artigo de periódico]The energy straggling of proton beams in SiO₂ has been measured in the energy range from 30 to 1500 keV using the transmission, nuclear reaction analysis and Rutherford backscattering techniques. The experimental results ... -
FECO-based observations of birefringence at normal incidence in optical coatings
(1985) [Artigo de periódico]Resumo não disponível -
Formation of epitaxial [Beta]-Sn islands at the interface of SiO/sub 2/Si layers implanted with Sn ions
(2005) [Artigo de periódico]180 nm SiO2 layers on Si s100d were implanted with Sn ions producing a profile with a peak concentration of 3 at. % at the middle of the oxide. After high temperature s900–1100 °Cd annealing, an array of b-Sn islands ... -
Gemini-Phoenix infrared high-resolution abundance analysis of five giants in the bulge globular cluster NGC 6553
(2003) [Artigo de periódico]A detailed abundance analysis of 5 giants of the metal-rich bulge globular cluster NGC 6553 was carried out using high resolution infrared spectra in the H band, obtained at the Gemini-South 8m telescope. JK photometry ... -
Improvement of SiO2/4H-SiC interface properties by oxidation using hydrogen peroxide
(2009) [Artigo de periódico]The effect of using H2O2 in the thermal growth process of dielectric films on n-type 4H-SiC substrates has been investigated. In comparison to conventional oxide growth using H2O, we found that the interface trap density ... -
Initial stages of SiC oxidation investigated by ion scattering and angle-resolved x-ray photoelectron spectroscopies
(2001) [Artigo de periódico]Initial stages of oxidation of single-crystal, Si-faced silicon carbide were investigated using ion scattering and angle-resolved x-ray photoelectron spectroscopies. The very first oxidation products are shown to be silicon ... -
Integrity of hafnium silicate/silicon dioxide ultrathin films on Si
(2002) [Artigo de periódico]Rapid thermal annealing at 1000 °C of (HfO2)12x(SiO2)x pseudobinary alloy films deposited on Si were performed in N2 or O2 atmospheres. The effects on the atomic transport, structure, and composition were investigated using ... -
Interaction of HfO/sub 2//SiO/sub 2/Si structures with deuterium gas
(2006) [Artigo de periódico]HfO2 films 2.5 to 12 nm deposited on thermal SiO2 1.5 nm on Si were annealed in deuterium gas at 400–600 °C and incorporated D amounts were quantified using the D 3He, p 4He nuclear reaction.We found 1013 D cm−2 in the ... -
Investigation of indirect structural and chemical parameters of GeSi nanoparticles in a silica matrix by combined synchrotron radiation techniques
(2012) [Artigo de periódico]The formation of GeSi nanoparticles on an SiO2 matrix is studied here by synchrotron-based techniques. The shape, average diameter and size dispersion were obtained from grazing-incidence small-angle X-ray scattering data. ... -
Ion beam synthesis of cubic-SiC layer on Si(111) substrate
(2006) [Artigo de periódico]We have investigated SiC layers produced by ion beam synthesis on Si (111) substrates using different procedures. Bare Si (111) and SiO2/Si (111) structures were implanted with carbon at 40 keV up to a fluence of 4 1017 ... -
Lift-off protocols for thin films for use in EXAFS experiments
(2013) [Artigo de periódico]Lift-off protocols for thin films for improved extended X-ray absorption fine structure (EXAFS) measurements are presented. Using wet chemical etching of the substrate or the interlayer between the thin film and the ... -
Limiting step involved in the thermal growth of silicon oxide films on silicon carbide
(2002) [Artigo de periódico]Thermal growth of silicon oxide films on silicon carbide in O2 was investigated using oxygen isotopic substitution and narrow resonance nuclear reaction profiling. This investigation was carried out in parallel with the ...
