ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
Cleavage plates of fluorite, CaF2, provide a simple and sensitive pressure calibration based on variation of the cubic unit-cell volume in high-pressure/high-temperature (PT) single-crystal diffraction experiments, when temperature is measured independently by thermocouple. Over the range 0 ≤ T ≤ 500°C and P ≤ 0.04 Mbar (4 GPa), the temperature–pressure–volume equation of state for CaF2 is approximately , where ΔV/Vo is the fractional change in cubic unit-cell volume from T = 0°C and P = 0 Mbar, T is temperature in °C, and P is pressure in Mbar. Crystal structures of CaF2 determined at several PT conditions are evidence of reversibility of single-crystal unit-cell parameters with heating and compression. Nonreversible changes occurred in observed temperature factors and extinction parameter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889881009266
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