Home Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]
Article
Licensed
Unlicensed Requires Authentication

Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]

Published/Copyright: August 25, 2010
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Zeitschrift für Kristallographie - Crystalline Materials
From the journal Zeitschrift für Kristallographie - Crystalline Materials Volume 149 Issue 3-4

Abstract

New results on the title dimorphism are given for the systems SrGa2Si208 – SrGa2Ge208, BaGa2Si2Og – BaGa2Ge2O8 and BaGa2Ge2Og – SrGa2Ge2O8. Their end terms as well as several intermediate terms were obtained by dry syntheses (reaction in the solid state or crystallization from the melt) or hydrothermally under 1.0 Kbar water pressure at 500° C. The proxying of Ge for Si, or of Sr for Ba, is accompanied by the shrinkage of the feldspar stability field which is progressively confined to the higher temperatures at room pressure. The composition limits for obtaining this form are SrGa2(Si0.75Ge0.25)2O8 and (Ba0.25Sr0.75) Ga2Ge2O8. The paracelsian form was obtained for all the Sr and Ba gallosilicates and germanates. The general effect of the hydrothermal conditions is of stabilizing this form.

The phase transition and the stability relations of the two forms are considered for all the title terms: the feldspar/paracelsian transition is enantiotropic only within the intervals: Sr(Al0.50Ga0.50)2Si2O8 – SrGa2Si2O8, SrGa2Si2O8 – (Sr0.50Ba0.50)Ga2Si2O8 and BaGa2(Si0.50Ge0.50)2O8 –BaGa2Ge208. The correlations between the stability conditions, the densities, and certain structural parameters are examined.

Published Online: 2010-8-25
Published in Print: 1979-2-1

© 2015 Oldenbourg Wissenschaftsverlag GmbH, Rosenheimer Str. 145, 81671 München

Articles in the same Issue

  1. Die Kristallstruktur von PbGe3O7 mit Ge4 + in trigonal-dipyramidaler neben tetraedrischer Koordination
  2. Zur Gitterkonstantenbestimmung mit Ausgleichsmethoden
  3. AB2X2-Verbindungen im CaAl2Si2-Typ, VI Zur Struktur von ThCu2P2, YbZn2P2 und YbZnCuP2 sowie der verwandten Verbindungen YbCu3P2 und YbCu2P2
  4. Die Kristallstruktur der ferroischen Verbindung Pb3[O|GeO4]
  5. Absorption corrections for equatorial back-reflections from a thin highly-absorbing plate-shaped crystal
  6. Posnjakite: 2∞[Cu4(OH)6(H2O)O] octahedral sheets in its structure
  7. Use of the integrated minimum function in heavy-atom structures
  8. Crystal growth, structure, and physical properties of Bi2Ge3O9
  9. Electrogyration effect in the paraelectric phase of ferroelectric alums
  10. Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]
  11. Non-existent silicates
  12. Crystal synthesis and structure refinement of high-pressure ScAlO3 perovskite
  13. A new phase of coesite SiO2
  14. Verfeinerung der Kristallstruktur des Silberperchlorats AgClO4
  15. The Neutron scattering amplitude of Uranium
  16. Kleber, W.: Einführung in die Kristallographie. 13., stark überarbeitete Auflage. 392S., 358 Abb., 45 Tafeln und 1 Beilage. Berlin: VEB Verlag Technik 1977. Geb. DM 32,– ; DDR M 24,80
  17. Lockwood, E. H., Macmillan, R. H.: Geometrie Symmetry (Geometrische Symmetrie). 288 S., mit zahlreichen Abbildungen und Tabellen. Cambridge: Cambridge University Press 1978. £10.50
https://doi.org/10.1524/zkri.1979.149.3-4.279

Articles in the same Issue

  1. Die Kristallstruktur von PbGe3O7 mit Ge4 + in trigonal-dipyramidaler neben tetraedrischer Koordination
  2. Zur Gitterkonstantenbestimmung mit Ausgleichsmethoden
  3. AB2X2-Verbindungen im CaAl2Si2-Typ, VI Zur Struktur von ThCu2P2, YbZn2P2 und YbZnCuP2 sowie der verwandten Verbindungen YbCu3P2 und YbCu2P2
  4. Die Kristallstruktur der ferroischen Verbindung Pb3[O|GeO4]
  5. Absorption corrections for equatorial back-reflections from a thin highly-absorbing plate-shaped crystal
  6. Posnjakite: 2∞[Cu4(OH)6(H2O)O] octahedral sheets in its structure
  7. Use of the integrated minimum function in heavy-atom structures
  8. Crystal growth, structure, and physical properties of Bi2Ge3O9
  9. Electrogyration effect in the paraelectric phase of ferroelectric alums
  10. Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]
  11. Non-existent silicates
  12. Crystal synthesis and structure refinement of high-pressure ScAlO3 perovskite
  13. A new phase of coesite SiO2
  14. Verfeinerung der Kristallstruktur des Silberperchlorats AgClO4
  15. The Neutron scattering amplitude of Uranium
  16. Kleber, W.: Einführung in die Kristallographie. 13., stark überarbeitete Auflage. 392S., 358 Abb., 45 Tafeln und 1 Beilage. Berlin: VEB Verlag Technik 1977. Geb. DM 32,– ; DDR M 24,80
  17. Lockwood, E. H., Macmillan, R. H.: Geometrie Symmetry (Geometrische Symmetrie). 288 S., mit zahlreichen Abbildungen und Tabellen. Cambridge: Cambridge University Press 1978. £10.50
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 28.9.2025 from https://www.degruyterbrill.com/document/doi/10.1524/zkri.1979.149.3-4.279/html
Scroll to top button