Low-temperature NIR-VUV optical constants of (001) LaAlO.sub.3./sub. crystal

0560878 - FZÚ 2023 RIV US eng J - Článek v odborném periodiku
Nepomniashchaia, Natalia - Vetokhina, Volha - Chvostová, Dagmar - Bryknar, Z. - Dejneka, Alexandr - Tyunina, Marina
Low-temperature NIR-VUV optical constants of (001) LaAlO₃ crystal.
Optical Materials Express. Roč. 12, č. 8 (2022), s. 3081-3089. ISSN 2159-3930
Grant CEP: GA MŠMT(CZ) EF16_019/0000760
Grant ostatní: OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institucionální podpora: RVO:68378271
Klíčová slova: low-temperature * ellipsometry * optical constants * LaAlO₃ crystal
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 2.8, rok: 2022
Způsob publikování: Open access

The optical constants and dielectric function of (001) LaAlO3 crystal were investigated at low temperatures down to 10 K in the NIR-VUV spectral range (photon energies 0.8-8.8 eV). Reflection variable angle spectroscopic ellipsometry and transmission spectroscopy were applied. Interband transitions were examined using the Tauc plots and the critical-point analysis. At room temperature, the indirect bandgap of 5.6 ± 0.01 eV and the lowest-energy direct transition at 7.2 ± 0.03 eV were detected. On cooling to 10 K, a blueshift of ∼0.2 eV and ∼0.1 eV was observed for the indirect and direct transitions, respectively. In the transparency spectral range, the index of refraction was found to be nearly temperature-independent and vary with photon energy from 2.0 (1 eV) to 2.5 (5.5 eV). It was suggested that the excellent thermal stability of the index of refraction may be related to the revealed thermally stable interband transitions.

Trvalý link: https://hdl.handle.net/11104/0333658