Effect of doping SrTiO.sub.3./sub. with Nb studied with wide-range spectroscopic ellipsometry

0574599 - FZÚ 2024 RIV US eng J - Journal Article
Nepomniashchaia, Natalia - Vetokhina, Volha - Chvostová, Dagmar - Bryknar, Z. - Tyunina, Marina - Dejneka, Alexandr
Effect of doping SrTiO₃ with Nb studied with wide-range spectroscopic ellipsometry.
Journal of Applied Physics. Roč. 134, č. 3 (2023), č. článku 034102. ISSN 0021-8979. E-ISSN 1089-7550
R&D Projects: GA ČR(CZ) GA22-10832S; GA MŠMT(CZ) EF16_019/0000760
Institutional support: RVO:68378271
Keywords : effect of doping SrTiO₃ with Nb * studied with wide-range spectroscopic ellipsometry * optical properties
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.2, year: 2022
Method of publishing: Open access

The low-temperature optical properties of a SrTiO3 crystal doped with 0.7% wt. Nb and a pure SrTiO3 reference crystal were studied using spectroscopic ellipsometry. The optical constants and dielectric functions were obtained in the spectral range of 0.8–8.8 eV at temperatures from 10 to 300 K, and the optical conductivity was obtained in the spectral range of 0.03–1 eV at 300 K. Analysis of the optical conductivity spectra in the infrared spectral range confirmed the presence of free electrons and additional absorption hump between 0.1 and 0.4 eV (806 and 3226 cm−1 ) in doped SrTiO3 and optical phonons in both doped and undoped SrTiO3. The performed analysis of optical absorption spectra in the range 0.8–8.8 eV revealed frustration of the indirect bandgap and an increase in the direct bandgap energy by ∼0.03 eV in Nb-doped SrTiO3 , compared to undoped SrTiO3 over the whole temperature range.
Permanent Link: https://hdl.handle.net/11104/0349501