Electro-optical and phonon properties of PbTiO3/CaTiO3/SrTiO3 ferroelectric superlattices: a first-principles calculation
| Autor: | Fariba Ahmadi, Houshang Araghi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Condensed matter physics Phonon Superlattice Physics::Optics Dielectric Condensed Matter Physics Ferroelectricity Optical conductivity Electronic Optical and Magnetic Materials Brillouin zone Condensed Matter::Materials Science Direct and indirect band gaps Density functional theory |
| Zdroj: | Journal of Nanophotonics. 15 |
| ISSN: | 1934-2608 |
| Popis: | We studied the electronic structure as well as the dielectric, optical, and phonon properties of PbTiO3 / CaTiO3 / SrTiO3 ferroelectric superlattices, based on the density functional theory, using the Perdew–Becke–Johnson-generalized gradient approximation exchange-correlation functional. According to the results, the superlattice under investigation possessed a semiconducting phase with an indirect band gap of 1.84 eV. The results obtained for the partial density of states were indicative of a strong hybridization between the Ti-3d and O-2p states, which affected the amplitude of the Coulomb interaction and ferroelectric property. Regarding the optical properties, we calculated and analyzed the dielectric function and, accordingly, the refractive index, reflectivity, absorption coefficient, energy loss function, and optical conductivity. Thermal vibrations of the lattice were calculated along the high-symmetry path of the first Brillouin zone. Phonon dispersion data revealed stability at point Γ, while ferroelectric and dielectric responses of superlattice could be in unstable modes at other points of the Brillouin zone. Our results comprehensively present the electronic structure, dielectric function, plasmonic features, and dynamical stability based on phonon calculations, which are all essential for novel functional device applications. |
| Databáze: | OpenAIRE |
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