Browsing by Author "Finch A."

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    Ionoluminescence of silicates for ceramic uses at cryogenic temperatures; [Ionoluminiscencia de silicatos de utilizacion en ceramica a temperaturas criogenicas]
    (Sociedad Espanola de Ceramica y Vidrio, 2004) Garcia-Guinea J.; Hole D.; Finch A.; Correcher V.; Valle-Fuentes F.J.; Can N.; Townsend P.D.
    Requirements on accurate physical properties need new characterization techniques for structural defects. The use of light ions such as H+ and He+ with MeV energies allows penetration to a depth of several microns in most materials producing strong luminescence to gain information on the defect structures present. Examples of ionoluminescence spectra of silicates for ceramic uses are included such as Mn2+-Fe3+ coupled pairs in quartz, Dy3+ in zircon, hatch-twinning in microcline and spontaneous strain and sodium in albite. In cryogenic thermal conditions tectosilicates display both, reorganization of Mn2+ and Fe 3+ centres plus a large enlargement of the UV-blue emissions by stress mechanisms. Nesosilicates, i.e., zircon, shows differences such as existence of REE and (Dy3+) and a selective reduction of some UV-blue peaks, e.g., at 340 and 400 nm.
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    Orientation dependence of the ion beam and cathodoluminescence of albite
    (2007) Garcia-Guinea J.; Finch A.; Can N.; Hole D.; Townsend P.
    Ion beam induced luminescence and cathodoluminescence of albite produce unexpected differences between (010) and (001) aligned samples. The emission spectra are modified by temperature and different components change in their relative intensity as a result of excitation by different ion beams of H +, H2 + and He+. A consideration of processes which can induce the orientation dependence and the role of excitation density that influences the component features are both discussed. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.