The thermal equation of state (TEOS) for solids is a mathematic model among pressure, temperature and density, and is essential for geophysical, geochemical, and other high pressure–temperature (high P–T) researches. However, in the last few decades, there has been a growing concern about the accuracy of the pressure scales of the calibrants, and efforts have been made to improve it by either introducing a reference standard or building new thermal pressure models. The existing thermal equation of state,
P-V-T equation of state of boron carbide
We report the P-V-T equation of state measurements
of B4C to 50GPa and approximately 2500K in
laser-heated diamond anvil cells. We obtain an
ambient temperature, third-order Birch–Murnaghan
fit to the P-V data that yields a bulk modulus K0
of 221(2) GPa and derivative, (dK/dP)0 of 3.3(1).
These were used in fits with both a Mie–Grüneisen–
Debye model and a temperature-dependent, Birch–
Murnaghan equation of state that includes thermal
pressure estimated by thermal expansion (α) and
a temperature-dependent bulk modulus (dK0/dT).
The ambient pressure thermal expansion coefficient
(α0+α1T), Grüneisen γ (V)=γ 0(V/V0)q and volumedependent
Debye temperature, were used as input
parameters for these fits and found to be sufficient to
describe the data in the whole P-T range of this study.
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- Award ID(s):
- 2119308
- NSF-PAR ID:
- 10447049
- Date Published:
- Journal Name:
- Philosophical transactions A
- Volume:
- 381
- ISSN:
- 2058-7457
- Page Range / eLocation ID:
- 20220331
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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