The negative thermo-optic effect in KTaO3: an ellipsometry study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F15%3A00235903" target="_blank" >RIV/68407700:21340/15:00235903 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.tandfonline.com/doi/abs/10.1080/01411594.2014.996757?journalCode=gpht20" target="_blank" >http://www.tandfonline.com/doi/abs/10.1080/01411594.2014.996757?journalCode=gpht20</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1080/01411594.2014.996757" target="_blank" >10.1080/01411594.2014.996757</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The negative thermo-optic effect in KTaO3: an ellipsometry study

Popis výsledku v původním jazyce

We used optical ellipsometry to study and elucidate the nature of the negative thermo-optic effect in KTaO3 single crystals, which consists of an increasing refraction index magnitude in the visible region upon cooling (dn/dT < 0). 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 -> ? 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 X5'upper -> X3 transitions (4.3?4.8 eV) were observed, which should be responsible for the nature of the observed negative thermo-optics in KTaO3.

Název v anglickém jazyce

The negative thermo-optic effect in KTaO3: an ellipsometry study

Popis výsledku anglicky

We used optical ellipsometry to study and elucidate the nature of the negative thermo-optic effect in KTaO3 single crystals, which consists of an increasing refraction index magnitude in the visible region upon cooling (dn/dT < 0). 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 -> ? 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 X5'upper -> X3 transitions (4.3?4.8 eV) were observed, which should be responsible for the nature of the observed negative thermo-optics in KTaO3.

Druh

O - Ostatní výsledky

CEP obor

BH - Optika, masery a lasery

OECD FORD obor

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Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů