Thermoelastic properties of grossular-andradite solid solution at high pressures and temperatures
Abstract
The pressure-volume-temperature (P-V-T) equation of state (EoS) of synthetic grossular (Grs)-andradite (And) solid-solution garnet sample have been measured at high temperature up to 900 K and high pressures up to 22.75 GPa for Grs50And50, by using in situ angle-dispersive X-ray diffraction and diamond anvil cell. Analysis of room-temperature P-V data to a third-order Birch-Murnaghan (BM) EoS yields: V0 = 1706.8 ± 0.2 Å3, K0 = 164 ± 2 GPa and K'0 = 4.7 ± 0.5. Fitting of our P-V-T data by means of the high-temperature third-order BM EoS gives the thermoelastic parameters: V0 = 1706.9 ± 0.2 Å3, K0 = 164 ± 2 GPa, K'0 = 4.7 ± 0.2, (∂K/∂T)P = -0.018 ± 0.002 GPa K-1, and α0 = (2.94 ± 0.07) × 10-5 K-1. The results also confirm that grossular content increases the bulk modulus of the Grs-And join following a nearly ideal mixing model. The relation between bulk modulus and Grs mole fraction (XGrs) in this garnet join is derived to be K0 (GPa) = (163.7 ± 0.7) + (0.14 ± 0.02) XGrs (R2 = 0.985). Present results are also compared to previously studies determined the thermoelastic properties of Grs-And garnets.
- Publication:
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Physics and Chemistry of Minerals
- Pub Date:
- February 2017
- DOI:
- 10.1007/s00269-016-0843-4
- Bibcode:
- 2017PCM....44..137F
- Keywords:
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- Grossular–andradite solid solution;
- Equation of state;
- High pressure and high temperature;
- X-ray diffraction;
- Diamond anvil cell