Luminescence and tenebrescence of natural sodalites: a chemical and structural study

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• 作者：Teresa Zahoransky ; Henrik Friis ; Michael A. W. Marks
• 刊名：Physics and Chemistry of Minerals
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：43
• 期：7
• 页码：459-480
• 全文大小：1,591 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Mineralogy
  Crystallography
  Geochemistry
  Mineral Resources
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-2021
• 卷排序：43

文摘

Sodalite (Naub>8ub>Alub>6ub>Siub>6ub>Oub>24ub>Club>2ub>) shows a wide range of colours and may exhibit a variety of optical properties including cathodoluminescence, photoluminescence and tenebrescence. These optical peculiarities are not yet fully understood but are of key interest for industry. We provide a detailed study on the photochromic properties of natural sodalite, and we show that S is crucially influencing luminescence of sodalites. A reduced intensity in cathodoluminescence was observed at high S contents for some samples, showing that S can act as cathodoluminescence quencher. Photoluminescent sodalites are generally enriched in S compared to non-photoluminescent samples, although few samples being very low in S still show photoluminescence. Additionally, S was found to enlarge the unit cell in natural sodalites which might have a crucial impact on their photochromic properties. The most efficient tenebrescent samples were found to be low in Fe, Mn and S. They showed the smallest unit-cell dimensions, and a strong link between the atomic structure and the formation of F-centres is proposed. Tenebrescence in natural sodalites appears to be enhanced (1) by S but saturated at too high S concentrations and (2) by a stoichiometry and structure close to the ideal sodalite composition. In contrast to the term self-quenching for luminescence, we propose a saturation of F-centres to explain tenebrescence at different S contents.KeywordsSodaliteLuminescenceTenebrescenceSulphur speciesStructureRaman spectroscopySelf-quenchingF-centres