| Autor: |
Gao G; Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA., Van Workum K, David Schall J, Harrison JA |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2006 Aug 16; Vol. 18 (32), pp. S1737-50. Date of Electronic Publication: 2006 Jul 25. |
| DOI: |
10.1088/0953-8984/18/32/S05 |
| Abstrakt: |
The elastic constants of diamond between 100 and 1100 K have been calculated for the first time using molecular dynamics and the second-generation, reactive empirical bond-order potential (REBO). This version of the REBO potential was used because it was redesigned to be able to model the elastic properties of diamond and graphite at 0 K while maintaining its original capabilities. The independent elastic constants of diamond, C(11), C(12), and C(44), and the bulk modulus were all calculated as a function of temperature, and the results from the three different methods are in excellent agreement. By extrapolating the elastic constant data to 0 K, it is clear that the values obtained here agree with the previously calculated 0 K elastic constants. Because the second-generation REBO potential was fit to obtain better solid-state force constants for diamond and graphite, the agreement with the 0 K elastic constants is not surprising. In addition, the functional form of the second-generation REBO potential is able to qualitatively model the functional dependence of the elastic constants and bulk modulus of diamond at non-zero temperatures. In contrast, reactive potentials based on other functional forms do not reproduce the correct temperature dependence of the elastic constants. The second-generation REBO potential also correctly predicts that diamond has a negative Cauchy pressure in the temperature range examined. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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