High Temperature Elastic Constants and the Evaluation of Effective Pair Potentials
Raymond D Mountain1, Donald C Knauss1
1National Bureau of Standards, Washington, D.C. 20234.
Journal of Research of the National Bureau of Standards (1977)
|September 27, 2021
Summary
The temperature dependence of elastic constants is a key test for effective pair potentials in metals. A model for aluminum showed this potential inaccurately predicts high-temperature properties.
Area of Science:
- Materials Science
- Computational Physics
- Condensed Matter Physics
Background:
- Effective pair potentials are crucial for modeling metal properties.
- Accurate prediction of thermal properties requires reliable potentials.
- Existing potentials are often validated only at low temperatures.
Purpose of the Study:
- To evaluate the utility of predicted temperature dependence of elastic constants.
- To assess the effectiveness of a model pair potential for aluminum.
- To determine the high-temperature thermal properties of metals.
Main Methods:
- Developed a model pair potential for aluminum.
- Calculated low-temperature elastic constants and phonon dispersion.
- Employed the Monte Carlo method to determine high-temperature elastic constants.
Main Results:
- The model potential accurately predicted low-temperature elastic constants (± a few percent).
- High-temperature elastic constants were predicted to be nearly independent of temperature.
- This contrasts with aluminum's known strongly temperature-dependent elastic constants.
Conclusions:
- The predicted temperature dependence of elastic constants is a valuable metric for pair potentials.
- The tested potential is inadequate for estimating high-temperature properties of aluminum.
- This temperature-dependence test should supplement existing low-temperature validation methods for potentials.
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