Nonlinear elasticity of ε -Fe: The pressure effect
| Autor: | A. V. Lugovskoy, Yu. Kh. Vekilov, M. P. Belov, Igor A. Abrikosov, O. M. Krasilnikov, Vladimir Dikan |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Linear elasticity education Thermodynamics 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Pressure range Condensed Matter::Materials Science Third order 0103 physical sciences Elasticity (economics) 010306 general physics 0210 nano-technology Nonlinear elasticity |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Description of elasticity of iron at the ultrahigh pressures is a challenging task for physics, with a potential strong impact on other branches of science. In the present work, we calculate the elastic properties of hcp iron in the pressure range of 50--340 GPa beyond the linear elasticity approximation, conventionally assumed in theoretical studies. We define the higher order elastic constants and present expressions for the long-wave acoustic modes Gr\"uneisen parameters of a compressed hcp crystal. We obtain the second and third order elastic constants of the hcp Fe in the considered pressure interval, as well as its Gr\"uneisen parameters for the high-symmetry directions. The latter are directly compared with the Gr\"uneisen parameters derived from the volume dependences of the vibrational frequencies calculated in the quasiharmonic approximation. The obtained results are used for the stability analysis of the hcp phase of iron at high pressures. |
| Databáze: | OpenAIRE |
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