Ab initio calculations of structural, phonon and thermal properties of Co2MnGe and Co2MnSi

Document Type : Full length research Paper

Authors

Assistant Professor Of Physics,Department Of Physics, Rasht Branch, Islamic Azad University, Rasht, Iran

Abstract

In this paper, structural, phonon and thermal properties of Co2MnGe and Co2MnSi calculated and have been compared with each other. Structural properties of these alloys have a good agreement with other experimental and theoretical works. By using density functional perturbation theory and Quantum Espresso package, phonon dispersion calculation in different directions have been done. Calculation of total and partial phonon density of states demonstrated that by increasing of mass of atoms their contributions decrease at higher frequencies. Also, calculations of specific heat at constant volume and Debye temperature by quasi-harmonic Debye-Einstein model and GIBBS2 package have been performed by considering only phonon contribution in the temperatures range of 0K to 900K which have a good consistency with other theoretical works. Specific heat at low temperatures has T3 behavior, while it trend to saturation limit at high temperatures. Debye temperature decrease by increasing temperature slowly.

Keywords

References

 
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Journal of Research on Many-body Systems
Volume 8, Issue 17
September 2018
Pages 95-102

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History

  • Receive Date: 16 September 2017
  • Revise Date: 14 February 2018
  • Accept Date: 07 May 2018

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