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Ferroelastic phase transition in SrAl2Si2O8 feldspar at elevated pressure

Published online by Cambridge University Press:  05 July 2018

M. D. McGuinn
Affiliation:
Department of Geology, The University, Manchester, M13 9PL, United Kingdom
S. A. T. Redfern
Affiliation:
Department of Geology, The University, Manchester, M13 9PL, United Kingdom

Abstract

Synthetic end-member strontium feldspar (SrAl2Si2O8) has been studied in a diamond-anvil cell at elevated pressures up to 10.3 GPa using energy-dispersive X-ray powder diffraction. Cell parameters have been refined between ambient pressure and 6 GPa. SrAl2Si2O8 undergoes a ferroelastic phase transition from the ambient pressure monoclinic space group I2/c to the high-pressure triclinic space group I at 3.2 ± 0.4 GPa. The transition appears to be first-order and the ferroelastic and co-elastic components of the spontaneous strain tensor have been calculated.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

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