Hydrostatic compression of γ-Mg2SiO4to mantle pressures and 700 K: Thermal equation of state and related thermoelastic properties
✍ Scribed by Y. Meng; Y. Fei; D. J. Weidner; G. D. Gwanmesia; J. Hu
- Publisher
- Springer-Verlag
- Year
- 1994
- Tongue
- English
- Weight
- 553 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0342-1791
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✦ Synopsis
P-V-T equations of state for the y phase of Mg2SiO 4 have been fitted to unit cell volumes measured under simultaneous high pressure (up 30 GPa) and high temperature (up to 700 K) conditions. The measurements were conducted in an externally heated diamond anvil cell using synchrotron x-ray diffraction. Neon was used as a pressure medium to provide a more hydrostatic pressure environment. The P-V-Tdata include 300 K-isothermal compression to 30GPa, 700K-compression to 25 GPa and some additional data in P-T space in the region 15 to 30 GPa and 300 to 700 K. The isothermal bulk modulus and its pressure derivative, determined from the isothermal compression data, are 182(3)GPa and 4.2(0.3) at T= 300 K, and 171(4) GPa and 4.4(0.5) at T-700 K. Fitting all the P-V-T data to a high-temperature Murnaghan equation of state yields: K~0= 182(3.0) GPa, Kro =4.0(0.3), (0Kr/07)o= -2.7(0.5)x 10 .2 GPa/K and (O2K~/0POT)o--5.5(5.2) x 10-4/K at the ambient condition.