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- ItemMulti-method characterization of soda-lime glass corrosion : Part 1. Analysis techniques and corrosion in liquid water Report of the International Commission on Glass (ICG) Subcommittee of Technical Committee 19 "Glass Surface Diagnostics"(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2001) Bange, Klaus; Anderson, Olaf; Rauch, Friedrich; Lehuédé, Patrice; Rädlein, Edda; Tadokoro, Nobuyuki; Mazzoldi, Paolo; Rigato, Valentino; Matsumoto, Kiyoshi; Farnworth, MarkCorroded soda-lime float glass surfaces prepared in water (room temperature and 60 °C) or air (relative humidity of 95 %, 60 °C) for different times are invesdgated by means of SIMS, SNMS, XPS, NRA, ERD, RBS, GIXR, AFM, SEM, light microscopy and scratch testing. The corrosion effects are studied for as-received and cleaned glass surfaces. Changes in the dement concentration in the glass interfaces with the immersion time in water are described. They are combined with variations in density of the surface layer which exhibits plastic deformation behaviour. Inhomogeneous corrosion leads to changes in the topography and an increase in surface roughness.
- ItemMulti-method characterization of soda-lime glass corrosion : Part 2. Corrosion in humidity Report of the International Commissionon Glass (ICG) Subcommittee of Technical Committee 19 "Glass Surface Diagnostics"(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2002) Bange, Klaus; Anderson, Olaf; Rauch, Friedrich; Lehuédé, Patrice; Rädlein, Edda; Tadokoro, Nobuyuki; Mazzoldi, Paolo; Rigato, Valentino; Matsumoto, Kiyoshi; Farnworth, MarkAs-received and cleaned soda-lime glass surfaces corroded in high relative humidity of 95 % at a temperature of 60 °C for times up to one week are investigated by means of TOF-SIMS, SNMS, XPS, NRA, ERD, RBS, GIXR, AFM, SEM and optical microscopy. Distinct differences in the corrosion behavior are observed for as-received and cleaned glass surfaces. Changes in element concentration in the glass interface and in the topography of the glass surfaces are described for different exposure times in humidity. They are combined with variations in density of the modified surface layer. Cleaning before the corrosion treatment drastically reduces degradation; cleaning after the corrosion treatment can restore the surface.
- ItemPractical IR extinction coefficients for water in commercial glasses determined by nuclear reaction analysis(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2000) Ilievski, Stamenko; Dersch, Oliver; Kinkel, Stefan; Maldener, Joachim; Zouine, Abdelkader; Rauch, Friedrich; Haspel, Rainer; Krämer, Fritz W.For a number of commercial glasses with different chemical compositions the water contents were determined by nuclear reaction analysis (NRA) measurements. These results were used to deduce practical extinction coefficients by comparison with the measured IR absorbance values at 2.8 μm. For aluminosilicate and television glasses the practical molar extinction coefficients are given for the first time. Practical extinction coefficients are dependent upon glass composition. With increasing basicity of the glasses studied they decrease from 182 to 24 l/(mol cm).
- ItemComposition of titania coatings deposited by different techniques(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1994) Laube, Michael; Wagner, Wolfgang; Rauch, Friedrich; Ottermann, Clemens; Bange, Klaus; Niederwald, HansjörgQuantitative dement concentrations in titania films produced by different deposition techniques (evaporation, sputtering, ion-assisted deposition, ion plating and dip coating) have been determined by means of Rutherford Backscattering Spectrometry and Nuclear Reaction Analysis with the reaction ¹H(¹⁵N, αγ)¹²C. Large differences of the hydrogen content are found for the various production techniques and the related deposition parameters, which correlate with the refractive index of the respective film. In dependence on the deposition conditions the oxygen/titanium ratio of the investigated titania films varies between 1.95 and 2.09. The impurities detected in the films (tantalum, molybdenum, silicon, argon, carbon, sodium) can be related to specific deposition conditions. Three multilayer interference systems containing TiO₂ and SiO₂ show large variations in hydrogen content resembling those found for single TiO₂ films.
- ItemDetermination of the water content of alkali lime silica glasses by IR spectroscopy using nuclear reaction analysis for calibration(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1998) Harder, Ulrike; Geißler, Heinz; Gaber, Martin; Hähnert, Manfred; Dersch, Oliver; Rauch, FriedrichSystematic IR and NRA investigations were performed for two series of glasses with very different water contents. The glasses had the composition (in mol%): 16 R₂O · 10 CaO · 74 SiO₂ (R = sodium, potassium). The IR absorption coefTicients of the OH bands were found to be linearly correlated with the total hydrogen content obtained by the NRA measurements. Using the hydrogen concentration values from NRA, the total water contents were calculated and so-called practical IR extinction coefTicients were deduced. The values found for the soda-lime-silica glasses are 381 · mol¯¹ · cm¯¹ for the band at 3550cm¯¹ and 561 · mol¯¹ · cm¯¹ for the band at 2800cm¯¹. The values for the potassium-lime-silica glasses are 231 · mol¯¹ · cm¯¹ for the band at 3550 cm¯¹ and 78 l · mol¯¹ · cm¯¹ for the band at 2800 cm¯¹ Also, Scholze's two-band method was applied, resulting in good agreement between the water contents of the glasses derived from the IR and the NRA measurements.
- ItemHydrogen/lithium interdiffusion in a lithium aluminosilicate glass studied by NRA and RBS(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1999) Dersch, Oliver; Laube, Michael; Rauch, Friedrich; Becker, OtmarSamples of a lithium aluminosilicate (LAS) glass, a model glass for technical LAS glass used in the production of glass ceramics, were treated in hot sulfuric acid and analyzed using Nuclear Reaction Analysis (NRA) techniques for determining hydrogen and lithium depth profiles in the surface layer. It was found that the depth profiles of these two elements are fully complementary, showing that H⁺/Li⁺ ion exchange takes place during the treatment. As revealed by Rutherford Backscattering Spectrometry (RBS) measurements the other glass constituents were not affected by the treatment.
- ItemIn-depth analysis of elements and properties of hydrated subsurface layers on optical surfaces of a SiO2-BaO-B2O3 glass with SIMS, IBSCA, RBS and NRA Part 1. Experimental procedures and results(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1987) Bach, Hans; Großkopf, Klaus; March, Peter; Rauch, FriedrichThe formation of thin subsurface layers was studied which occurred during the chemical interaction of polished and cleaned optical surfaces with different slurries before and after covering them with λ/4-MgF2 coatings. By a suitable selection of the parameters for these chemical interactions a thickness of the subsurface layers was produced which allowed to meet the requirements of the various surface analysis methods. The thicknesses and the refractive indices of the subsurface layers could be calculated from the measured spectral reflectances. Slurries with a pH value < 9 were applied so that a leaching of glass components from the subsurface layers occurred. This was indicated by the refractive indices and was studied in detail by analyzing the in-depth distributions of the glass components. Distinct matrix effects could be disclosed from the in-depth profiles for SIMS and IBSCA by a comparison with the results of the quantitative analysis with RBS and NRA. These matrix effects were different within the subsurface layers from those observed for the bulk glass. The quantitative analysis of the hydrogen in-depth distributions by NRA allows for the first time to link differences in the matrix effects with a different hydrogen content within the subsurface layers.
- ItemLeaching studies of soda-lime-silica glass using deuterium- and 18O-enriched solutions(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1990) March, Peter; Rauch, FriedrichWith a glass of composition (in mol%) 74 SiO2, 16 Na2O, 10 CaO, various leaching experiments were conducted, in which besides solutions of normal isotopic composition deuterium- and 18O-enriched solutions were used. The concentration profiles of deuterium, hydrogen, and 18O in the sample were measured with nuclear analyzing techniques. Α distinct H/D isotope effect was observed, showing that hydrogen takes part in the rate-determining step of leaching. The measured ratio of 18O uptake to hydrogen uptake during leaching gives evidence for exchange of oxygen between the glass network and water molecules contained in the leached layer. From measurements on the exchange of hydrogen and oxygen between solution and leached layer, a high mobility of water molecules in the leached layer and evidence for condensation of silanol groups was found.
- ItemChemical properties of hydrolyzed surface layers on SiO2-BaO-B2O3(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1990) Wagner, Wolfgang; Rauch, Friedrich; Bach, HansThe leaching process of SiO2—BaO—B2O3 glass in distilled water and the subsequent processes during storage in air were studied to complete the recent investigations on the interaction of SiO2—BaO—B2O3 glass with polishing slurries. The in-depth distributions of hydrogen and glass constituents existing in the leached surface layers were measured using nuclear reaction analysis and Rutherford backscattering spectrometry. Hydrogen uptake, barium loss and redeposition of dissolved zirconium-containing material on the surface occurred during the interaction with water. Changes of the in-depth distributions caused by reactions between the molecular water from the air, the materials of the leached surface layers and the glass components during a subsequent storage in air at room temperature were also observed. The analyses show unequivocally that the chemical driving forces of these reactions exhibit differences which depend exclusively on the different chemical properties of the leached surface-layer materials. These properties are on their part determined by different leaching agents and parameters. Consequences for the control of chemical interactions of silicate glass surfaces during the fabrication of optical surfaces are considered.
- ItemOn the mechanism of diffusion of water in silica glass(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1993) Helmich, Michael; Rauch, FriedrichDiffusion of water into silica glass has been studied at low temperatures. Hydrothermal treatments were made with water of normal isotopic composition and water enriched in 18O. Hydrogen and 18O concentration profiles were measured employing nuclear reaction analysis. After short-term treatments (5 to 20 h) at temperatures between 100 and 200°C, the concentration ratio [^18O]/[H] was found to be 0.5. This allows the conclusion that water molecules are the diffusing species. Diffusion coefficients deduced from the profiles are D ≈ 3 ∙ 10^-13 cm^2/s at 200°C and D ≈ 6 ∙ 10^-15 cm^2/s at 100 °C; the corresponding activation energy is about 58 kJ/mol. The near-surface concentration of hydrogen and 18O increased with treatment time and temperature, indicating a nonequilibrium state. After long-term treatments (6 to 20 d) at 200 °C, the near-surface concentration of hydrogen was found to have a nearly constant value of 7 ∙ 10^20 atoms/cm^3, and [^180]/[H] ratios up to 1.7 were observed. It was concluded that an equilibrium or near-equilibrium state with regard to the concentrations of H2O molecules and SiOH groups had been reached, the SiOH groups being formed by (reversible) reactions of H2O molecules with the SiO2 network. These findings are discussed in the framework of the diffusion model of Doremus.