Abstract
The volume thermal expansion of powdered natural orthoenstatite [(Mg0.994Fe0.002Al0.004 2(Si0.996AAl0.004 2O6] has been measured to 1473 K using energy dispersive synchrotron X-ray diffraction. Over the temperature range examined, the data are consistent with a volume thermal expansion, α, that linearly increases with temperature as given by the expression α(T) = 29.7(16) × 10-6K-1 + 5.7(11) × 10-9 K-2T. An analysis in terms of the often-used constant expansion coefficient yields αo=34.5(17) × 10-6 K-1, which is in good agreement with several previous experimental results on orthoenstatite (Mg2Si2O6) over a similar temperature range. Our results do not support the extreme upper and lower bounds reported in earlier studies for the thermal expansivity of Fe-rich orthoenstatite, but rather suggest that the thermal expansion of this phase is approximately midway between those extreme values.
Original language | English (US) |
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Pages (from-to) | 469-473 |
Number of pages | 5 |
Journal | European Journal of Mineralogy |
Volume | 15 |
Issue number | 3 |
DOIs | |
State | Published - 2003 |
Keywords
- High-temperature
- Orthoenstatite
- Thermal expansion
- X-ray diffraction
ASJC Scopus subject areas
- Geochemistry and Petrology