First principles prediction of structural stability, elastic, lattice dynamical and thermal properties of osmium carbides


Deligoz E., Ozisik H. B. , Colakoglu K., Ciftci Y.

MATERIALS SCIENCE AND TECHNOLOGY, vol.30, no.7, pp.842-849, 2014 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 7
  • Publication Date: 2014
  • Doi Number: 10.1179/1743284713y.0000000420
  • Journal Name: MATERIALS SCIENCE AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.842-849
  • Keywords: Ab initio calculations, Elastic properties, Thermodynamical properties, Carbides, TOTAL-ENERGY CALCULATIONS, AB-INITIO, THERMODYNAMIC PROPERTIES, PHASE-TRANSITION, HIGH-PRESSURE, TEMPERATURE, HARDNESS, RHENIUM

Abstract

First principles calculations are performed to investigate the structural stability, elastic, lattice dynamical and thermal properties of osmium carbides with various crystal structures. Our calculation indicates that the I4Te type structure is energetically the most favourable for Os4C. Based on stress-strain relationships, elastic constants are obtained, and the relevant mechanical properties are also discussed. The phonon dispersion relation and the dynamical stability are also predicted. We have found that the predicted structures are mechanically stable as well as dynamically stable except for cubic-Os4C. Through the quasi-harmonic Debye model, the temperature and pressure effects on the bulk modulus, thermal expansion coefficient, heat capacity, Gruneisen parameter and Debye temperature are presented.