Optical properties of SiC for crystalline/amorphous pattern fabrication

Derst, G.; Wilbertz, Ch.; Bhatia, K.L.; Krätschmer, W.; Kalbitzer, S.

doi:10.1063/1.101271

Cited by 50 publications

(22 citation statements)

References 6 publications

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“…Because of the strong absorption in the energy range of the laser wavelength, the penetration depth of the laser beam is strongly decreased (typically the penetration depth decreases to a few tens of nanometer in heavy coloured sample 30,31 ) and the Raman signature of the red Cu 0 n samples is essentially a surface phenomenon. 2.…”

Section: Discussionmentioning

confidence: 99%

Raman signature modification induced by copper nanoparticles in silicate glass

Colomban

Schreiber

2005

J. Raman Spectrosc.

118

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Composite materials formed by metal nanoclusters embedded in glasses/glazes have been produced for centuries (Roman hematinum and Renaissance alassonti, Coptic lustre-painted glass and Islamic lustre ceramics). Comparisons were drawn from Raman analyses of alkali borosilicate glasses coloured by copper as 'blue' Cu 2+ (peak absorption at 750 nm), as 'colourless' Cu + and as 'opaque red' Cu 0 (peak absorptions at ∼420 and 570 nm). In particular, Raman analyses of copper-ruby glasses containing Cu 0 nanocrystals were performed with blue (488 nm), green (514.5 and 532 nm) and red (647.1 nm) excitation, providing information on the glass structure around the Cu 0 precipitate. Addition of europium to Cu 0 -containing glass melts yielded glasses that were dichroic; for example, a glass with 0.2 wt% Cu and 0.4 wt% Eu was red in absorbed light and blue in transmitted light. The backscattering Raman signature of the glassy silicate matrix containing copper indicated a less-polymerized network around the Cu 0 nanocrystals/atoms than around Cu 2+ or Cu + (Raman index of polymerization ∼1 instead of ∼2). Strong Rayleigh scattering is measured under blue excitation for all copper-containing glasses and under red excitation for Cu 0 -containing (red) glass.

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Section: Discussionmentioning

confidence: 99%

Raman signature modification induced by copper nanoparticles in silicate glass

Colomban

Schreiber

2005

J. Raman Spectrosc.

118

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“…21 It was found that the laser penetration decreases when the electronic absorption increases and is expected to be only a few hundred nanometres (or even less) in carbon-containing materials. Resonant Raman spectra are expected from SiC fibre carbon moieties with all of our laser lines and, as a result, the Raman cross-section of carbon is much higher than that of SiC.…”

Section: Analysed Volumementioning

confidence: 99%

Skin/bulk nanostructure and corrosion of SiC‐based fibres: a surface Rayleigh and Raman study

Havel¹,

Colomban²

2003

J Raman Spectroscopy

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SiC-based fibres are complex systems of nanophases. Raman imaging of polished Tyranno SA3 fibre (UBE Industry) sections indicated that carbon species have different concentrations, natures and short-range order on the fibre core and surface, which results from the production process. The monitoring of the fibre's skin/bulk nanostructure, composition and geometry was performed on sections by Raman and Rayleigh microspectrometry. Owing to the weak light penetration in these materials, Rayleigh diffusion can map the surface geometry. The spatial correlation model applied to the LO SiC Raman mode at ca 969 cm −1 allowed us to estimate the size variation of the small SiC crystallites across the fibre. A model based on the I D /I G Raman peak ratio was used to calculate and map the size distribution of the carbon moieties. The position of the D Raman peak at ca 1620 cm −1 , which is correlated with the graphite in-plane lattice contraction or expansion, allowed us to identify the intercalant ions. The fibre's core, which contains non-aromatic carbon moieties, is corroded much faster than the periphery under an alkaline and oxidative environment (modelled by molten NaNO 3 and LiNO 3 ). This is considered to be linked to the nature of these carbon moieties and to their location (at triple points and grain boundaries), which constitutes a direct diffusion pathway.

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“…Fig. 2a compares the absorbency profile of powdered Hi-Nicalon fibers with electronic absorption tails for single crystals of bSiC [41 ± 43] and for a-SiC [44]. Due to the fast sedimentation in the inert solvent that was used, the absorbency level is arbitrary and only lineshape makes sense: Hi-Nicalon ªSiCº fibers exhibit a strong absorption in the full energy range, as observed for amorphous, carbon-rich, SiC films (see Fig.…”

Section: Carbon Resonancementioning

confidence: 99%

“…(a) Absorptionskurve von pulverfo Èrmigen SiC-(Hi-Nicalon)-und Kohlenstoff-(hochkristallines FT700)-Fasern, die in CCl 4 dispergiert sind. Die Werte fu Èr den Absorptionskoeffizient (cm À1 Einheit) sind denen fu Èr reines a-SiC [44] und b-SiC [41 ± 43] u Èberlagert; (b) Lichtpenetration in amorphen SiC-Filmen, nach Derst et al[44] …”

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Raman analysis of materials corrosion: the example of SiC fibers

Colomban

Gouadec

Mazérolles

2002

Materials and Corrosion

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Advanced materials (ceramics, fibers, composites...) exhibit unique high temperature properties but long term durability assessment is mandatory on account of high processing costs. We used Raman micro‐spectroscopy to analyze the corrosion resistance of commercially available SiC fibers versus Na+ ions, with or without fiber thermal treatment (in air or in a reducing atmosphere) prior to sodium attack. The lateral resolution of the technique approaches the submicron scale and the analysis of colored materials can be limited to a few tens of nanometers in‐depth, which makes Raman micro‐spectrometry well suited for the analysis of corrosion films. Although corrosion starts with localized defects in pristine NicalonTM fibers attacked with Na+ (in oxidizing conditions), a protective effect of a silica film is clear for oxidized fibers. The corrosion of SiC crystals seems to be related to stacking faults.

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Optical properties of SiC for crystalline/amorphous pattern fabrication

Abstract: A 100nm patterned xray mask technology based on amorphous SiC membranes

Cited by 50 publications

References 6 publications

Raman signature modification induced by copper nanoparticles in silicate glass

Raman signature modification induced by copper nanoparticles in silicate glass

Skin/bulk nanostructure and corrosion of SiC‐based fibres: a surface Rayleigh and Raman study

Raman analysis of materials corrosion: the example of SiC fibers

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