Electronic structure and optical properties of KNbO3: First principles study
SULEYMAN CABUK1,*
Affiliation
- Cukurova University, Faculty of Science and Letters, Physics Department, Adana, 01330, Turkey
Abstract
The electronic structures and optical properties of KNbO3 were studied from the first principles using density functional
theory. The energy band structures, dielectric function and optical constants of cubic and tetragonal phases are calculated
using pseudopotential with local density approximation. A direct band gap at Γ point and an indirect band gap R- Γ point in
the Brillouin zone are predicted for cubic and tetragonal phases. Both phases, the real and imaginary parts of the dielectric
function and hence the optical constants such as reflectivity, refractive index, extinction coefficient, electron energy-loss
function, eff ε (the optical dielectric constant) and eff N (the effective number of electrons) per unit cell are calculated. The
calculated spectra are compared with the experimental data in the orthorhombic phase and other theoretical results for
KNbO3 and are found to be in good agreement with the results.
Keywords
Electronic structure, Optical properties, Perovskite structure, KNbO3.
Citation
SULEYMAN CABUK, Electronic structure and optical properties of KNbO3: First principles study, Optoelectronics and Advanced Materials - Rapid Communications, 1, 3, March 2007, pp.100-107 (2007).
Submitted at: Dec. 19, 2006
Accepted at: Feb. 14, 2007