Ab initio calculations of structural, electronic, optical and thermodynamic properties of alkaline earth tellurides BaxSr1−XTe
| Autor: | L. Amirouche, Y. Bouhadda, Nouredine Fenineche, B. Deghfel, B. Bahloul, A. Bentabet, S. Bounab |
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| Rok vydání: | 2014 |
| Předmět: |
Bulk modulus
Internal energy Chemistry Thermodynamics General Chemistry Condensed Matter Physics symbols.namesake Ab initio quantum chemistry methods Helmholtz free energy symbols Physical chemistry General Materials Science Density functional theory Direct and indirect band gaps Local-density approximation Ternary operation |
| Zdroj: | Journal of Physics and Chemistry of Solids. 75:307-314 |
| ISSN: | 0022-3697 |
| DOI: | 10.1016/j.jpcs.2013.11.014 |
| Popis: | Structural, electronic and thermodynamic properties of SrTe and BaTe compounds and their ternary mixed crystals Ba x Sr 1−x Te in the rock-salt structure have been studied with density functional theory (DFT), whereas the optical properties have been obtained by using empirical methods such as the modified Moss relation. The exchange-correlation potential was calculated using the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) and the local density approximation (LDA) of Teter–Pade (TP). In the present work, we used the virtual-crystal approximation (VCA) to study the effect of composition ( x ). The calculated lattice parameters at equilibrium volume and the bulk modulus for x =0 and x =1 are in good agreement with the literature data. Furthermore, the Ba x Sr 1−x Te alloys are found to be an indirect band gap semiconductor. In addition, we have also predicted the heat capacities ( C V ), the entropy( S ), the internal energy ( U ) and the Helmholtz free energy ( F ) of the parent compounds SrTe and BaTe. |
| Databáze: | OpenAIRE |
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