000K  utf8
1100  $c2005
1500  ger
2050  urn:nbn:de:gbv:8-diss-15190
3000  Peters, Lars
4000  Gekoppelte Substitutionen im Melilith- und Sodalith-Strukturtyp$hChristian-Albrechts-Universität zu Kiel  [Peters, Lars]
4030  Kiel$nChristian-Albrechts-Universität zu Kiel
4209  Since its formulation 50 years ago, Loewenstein’s rule has become a standard argument in the crystal chemistry of, notably, layer and framework silicates and zeolites. The validity of the rule is usually taken for granted, and it is used rather schematically. The rule is normally used as an argument to account for two experimental observations: i) In alumosilicates, AlO4-tetrahedra tend to avoid each other, leading to alternating AlO4- and SiO4-tetrahedra for a Si : Al ratio of 1:1; ii) Except in rare cases, alumosilicates have an Al : Si ratio smaller than or equal to 1. While observation i) could be rationalized theoretically, observation ii) is not easily explained, in fact, it does not seem that fully convincing arguments have been put forward for its explanation. We have prepared series of compounds where Loewenstein’s rule is breached systematically, and continuously. These belong either to the melilite, or to the sodalite structure type. Crystallographic, structural, chemical and physical features and properties have been determined and are reported.
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-15190$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/diss_mods_00001519
5051  540
5550  Aluminium-Avoidance-Rule
5550  Aluminium-Vermeidungs-Regel
5550  coupled substitution
5550  gekoppelte Substitution
5550  Loewenstein's Rule
5550  Löwensteinsche Regel
5550  melilite
5550  Melilith
5550  sodalite
5550  Sodalith