Temperature dependence of the optical properties of Ba0.75Sr0.25TiO3 thin films
| Autor: | V. Železný, Dagmar Chvostova, L. Pajasová, Tomáš Kocourek, Miroslav Jelinek, Stanislav Daniš, Václav Valvoda |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Condensed matter physics Band gap Metals and Alloys Analytical chemistry Surfaces and Interfaces Dielectric Spectral line Surfaces Coatings and Films Electronic Optical and Magnetic Materials Pulsed laser deposition Condensed Matter::Materials Science Ellipsometry Attenuation coefficient Materials Chemistry Thin film Electronic band structure |
| Zdroj: | Thin Solid Films. 571:416-419 |
| ISSN: | 0040-6090 |
| Popis: | Optical properties of Ba 0.75 Sr 0.25 TiO 3 (BST(75/25)) ferroelectric thin film have been investigated by spectroscopic ellipsometry in a broad temperature interval from 10 to 300 K. The polycrystalline perovskite-phase BST films were prepared by pulsed laser deposition technique. The complex dielectric functions and optical parameters of the films were determined in the 1.5–5.5 eV spectral range. The spectra can be divided into two distinctive regions according to the magnitude of absorption coefficient separated by a band gap. An apparent reduction of the band gap was observed on increasing temperature. This can be ascribed to the renormalization of electronic band structure due to the electron–phonon interaction, which follows the Bose–Einstein model. |
| Databáze: | OpenAIRE |
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