Počet záznamů: 1
The negative thermo-optic effect in KTa0.sub.3./sub. : an ellipsometry study
- 1.0450616 - FZÚ 2016 RIV GB eng J - Článek v odborném periodiku
Trepakov, Vladimír - Dejneka, Alexandr - Jastrabík, Lubomír - Lynnyková, Anna - Chvostová, Dagmar - Syrnikov, P. - Markovin, P.
The negative thermo-optic effect in KTa03 : an ellipsometry study.
Phase Transitions. Roč. 88, č. 10 (2015), s. 991-1000. ISSN 0141-1594. E-ISSN 1029-0338
Grant CEP: GA ČR GAP108/12/1941; GA MŠMT(CZ) LM2011029
Grant ostatní: SAFMAT(XE) CZ.2.16/3.1.00/22132
Institucionální podpora: RVO:68378271
Klíčová slova: KTa03 ellipsometry * band-edge optical transitions * thermo-optics
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 0.858, rok: 2015
We used optical ellipsometry to study and elucidate the nature of the negative thermo-optic effect in KTa03 single crystals, which consists of an increasing refraction index magnitude in the visible region upon cooling (dn/dT < O). The optical constant functions were determined within the 1-6 eV region. The energies of the band edge indirect and direct optical transitions and their temperature evolutions in the region of 80-300 K were carefully investigated. The absorption edge in the region of the lowest indirect R → Γ optical transitions, 3.7-4.2 eV, was observed to shift to higher energies upon cooling. Simultaneously, an increase and "red shift" of the optical absorption in the region of the direct transitions (4.3-4.8 eV) were observed, which should be responsible for the nature of the observed negative thermo-oplics in KTa03.
Trvalý link: http://hdl.handle.net/11104/0251882
Počet záznamů: 1