SrWO4 at high pressures

• Published in: Physica Status Solidi (b) Vol. 242; no. 14; pp. 2795 - 2802
• Main Authors: Grzechnik, A., Crichton, W. A., Hanfland, M.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-11-2005; WILEY‐VCH Verlag; Wiley
• Subjects: 07.35.+k; 61.10.Nz; 61.50.Ks; 62.50.+p; 64.70.Kb; Condensed matter: structure, mechanical and thermal properties; Equations of state of specific substances; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Physics; Solid-solid transitions; Specific phase transitions; Irreversible processes; Pressure effects; Equations of state; Phase transformations; Superstructure; Strontium Tungstates; Diamond anvil; XRD; High temperature; Synchrotron radiation; High pressure
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200540106

Room‐temperature high‐pressure behaviour of SrWO4 scheelite (I41/a, Z = 4) has been studied to 20.7 GPa in a diamond anvil cell using synchrotron angle‐dispersive X‐ray powder diffraction. Above 10 GPa, it transforms to the fergusonite structure (I2/a, Z = 4). Both scheelite and fergusonite types are ordered superstructures of fluorite (Fm$ \bar 3 $m, Z = 4). There is no significant volume collapse at the scheelite‐fergusonite phase transition. However, the compression data including both phases of strontium tungstate cannot be fitted by a common Birch–Murnaghan equation of state. An onset of decomposition into component oxides occurs at about 15 GPa. The pressure‐induced transformations are irreversible. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)