A wide-range multiphase equation of state for platinum
V M Elkin1, V N Mikhaylov1, A A Ovechkin1
1FSUE RFNC-VNIITF named after academ. E I Zababakhin, 456770, Snezhinsk, Russia.
Summary
This study introduces a new equation of state for platinum, covering melting, evaporation, and ionization. The model accurately predicts platinum
Area of Science:
- Materials Science
- Condensed Matter Physics
- Computational Physics
Background:
- Accurate equations of state (EOS) are crucial for understanding material behavior under extreme conditions.
- Platinum exhibits complex phase transitions (melting, evaporation, ionization) requiring sophisticated models.
Purpose of the Study:
- To develop a semi-empirical, wide-range equation of state for platinum.
- To accurately model platinum's thermodynamic properties across various states, including melting, evaporation, and ionization.
Main Methods:
- Utilized a genetic algorithm for parameter optimization across extensive experimental and calculated data.
- Integrated first-principles and average-atom model calculations for data-scarce regions.
- Developed an improved model for shear modulus in (V,T) coordinates.
Main Results:
- Calculated the melting curve of platinum up to 1 TPa.
- Determined sound velocities along the Hugoniot curve and melting parameters under shock compression.
- Characterized the critical point parameters and shock adiabat variations of shear modulus.
Conclusions:
- The developed semi-empirical EOS provides a robust framework for platinum under diverse conditions.
- The model enhances predictions of platinum's high-pressure and high-temperature behavior, including phase transitions.
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