https://doi.org/10.1140/epjb/e2008-00286-6
Electronic and optical properties under pressure effect of alkali metal oxides
1
Department of Physics, Faculty of Science, University of Chlef, 02000 Chlef, Algeria
2
Institute of Science & Technologie, Université of Mascara, 29000 Mascara, Algeria
3
Department of Physics, Faculty of Science, University of Setif, 19000 Setif, Algeria
4
Department of Physics, Faculty of Science, University of Sidi-Bel Abbès, 22000, Sidi-Bel Abbès, Algeria
5
Équipe de Chimie Physique, IPREM-UMR 5254, Université de Pau, Pau, France
Corresponding authors: a khenata_rabah@yahoo.fr - b a_bouhemadou@yahoo.fr
Received:
8
May
2008
Revised:
12
June
2008
Published online:
16
July
2008
We report results of first-principles calculations for the electronic and optical properties under pressure effect of Li2O, Na2O, Ki2O and Rb2O compounds in the cubic antifluorite structure, using a full relativistic version of the full-potential augmented plane-wave plus local orbitals (FP-APW+lo) method based on density functional theory, within the local density approximation (LDA) and the generalized gradient approximation (GGA). Moreover, the alternative form of GGA proposed by Engel and Vosko (GGA-EV) is also used for band structure calculations. The calculated equilibrium lattices and bulk moduli are in good agreement with the available data. Band structure, density of states, and pressure coefficients of the fundamental energy gap are given. The critical point structure of the frequency dependent complex dielectric function is also calculated and analyzed to identify the optical transitions. The pressure dependence of the static optical dielectric constant is also investigated.
PACS: 71.15.Ap – Basis sets / 78.40.Fy – Semiconductors / 78.20.Ci – Optical constants
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008