Abstract

Optical index of refraction n is studied by spectroscopic ellipsometry in epitaxial nanofilms of NaNbO3 with thickness ∼10 nm grown on different single-crystal substrates. The index n in the transparency spectral range (n ≈ 2.1 – 2.2) exhibits a strong sensitivity to atmospheric-pressure gas ambience. The index n in air exceeds that in an oxygen ambience by δn ≈ 0.05 – 0.2. The thermo-optical behaviour n(T) indicates ferroelectric state in the nanofilms. The ambience-sensitive optical refraction is discussed in terms of fundamental connection between refraction and ferroelectric polarization in perovskites, screening of depolarizing field on surfaces of the nanofilms, and thermodynamically stable surface reconstructions of NaNbO3.

Details

Title
Ambience-sensitive optical refraction in ferroelectric nanofilms of NaNbO3
Author
Tyunina, Marina 1 ; Chvostova, Dagmar 2 ; Oliva Pacherova 2 ; Kocourek, Tomas 2 ; Jelinek, Miroslav 2 ; Jastrabik, Lubomir 2 ; Dejneka, Alexander 2 

 Microelectronics and Materials Physics Laboratories, University of Oulu, PO Box 4500, FI-90014 Oulun yliopisto, Finland; Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic 
 Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic 
Publication year
2014
Publication date
Aug 2014
Publisher
Taylor & Francis Ltd.
ISSN
14686996
e-ISSN
18785514
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2332063662
Copyright
© 2014 National Institute for Materials Science. This work is licensed under the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.