Formation of metallic colloids in CaF₂ by intense ultraviolet light

Highest purity CaF2 single crystals are irreversibly modified when irradiated with millions of pulses of 193 nm light at fluences of 120 mJ/cm(2). Mie theory explains the observed haze by attributing the wavelength dependent extinction and the ratio between absorption and scattering to metallic colloids with radii in the range of 20 to 30 nm and a fractional volume of up to 2.8 . 10(-7). Non-contact scanning force microscopy (NC-AFM) measurements performed on a surface produced by in-vacuo cleavage reveals that laser irradiation additionally produces a 10(4) times higher volume density of colloids with a radius of 1 to 2 nm. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3673301

CHOCLAB II. Standardisierte Laserstrahl- und Optikcharakterisierung Abschlussbericht

SIGLEAvailable from TIB Hannover: F04B1113 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Trinkwasserdesinfektion mit Sonnenlicht. Teiprojekt 2: Glasentwicklung Abschlussbericht

It has been developed low cost colorless and by NiO or/and CoO colored glasses with high uv-b-transmission based on silicates (BG, AR) and borosilicates (BK7, Duran), with low solarization and crystallization ability, high hydrolytical resistance, and mechanical strength, in a laboratory scale. The influence of iron and other impurities on the uv transmission, and the redox equilibria of different polyvalent ions in melts and glasses, dotation of reducing substances [Sn(II)-oxalate, sugar, carbon, metals] had been investigated. Thermodynamical data of polyvalent ions in the melts were determined by electrochemical measurements depending on the temperature (1500-700 C). A comparison with the values obtained by optical spectroscopy was done. The results of the laboratory research could be transfered to a pilot scale (380 kg). The chemical resistance was determined at different pH values. The best stability was in the acid region. Solarization was investigated by uv lamp and uv laser irradiation. A model was developed estimating the long time effect of sun light irradiation. The effect of nickel in food from medical point of view was studied in the literature. (orig.)SIGLEAvailable from TIB Hannover: F99B310+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman