Phase behaviour, thermal expansion and compressibility of SnMo 2 O 8

Araujo, Luiza R.; Gallington, Leighanne C.; Wilkinson, Angus P.; Evans, John S.O.

Abstract

The phase behaviour and thermoelastic properties of SnMo2O8, derived from variable temperature and pressure synchrotron powder diffraction data, are reported. SnMo2O8 is a member of the AM2O8 family of negative thermal expansion (NTE) materials, but unexpectedly, has positive thermal expansion. Over the P-T space explored (298–513 K, ambient to 310 MPa) four different forms of SnMo2O8 are observed: α, β, γ and γ′. The γ to β transition is temperature-, pressure-, and time-dependent. SnMo2O8 is a much softer material (α and γ form have BT = 29 and 26 GPa at 298 K) than other members of the AM2O8 family. Counter-intuitively, its high temperature β phase becomes stiffer with increasing temperature (BT ∼36 GPa at 490 K). The pressure dependence of the thermal expansion for each phase is reported.

Citation

Araujo, L. R., Gallington, L. C., Wilkinson, A. P., & Evans, J. S. (2018). Phase behaviour, thermal expansion and compressibility of SnMo 2 O 8. Journal of Solid State Chemistry, 258, 885-893. https://doi.org/10.1016/j.jssc.2017.08.040

• Journal Article Type: Article
• Acceptance Date: Aug 24, 2017
• Online Publication Date: Sep 6, 2017
• Publication Date: Feb 1, 2018
• Deposit Date: Feb 1, 2018
• Publicly Available Date: Sep 6, 2018
• Journal: Journal of Solid State Chemistry
• Print ISSN: 0022-4596
• Electronic ISSN: 1095-726X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 258
• Pages: 885-893
• DOI: https://doi.org/10.1016/j.jssc.2017.08.040