An optical and dielectric spectroscopy study of Er.sup.3+./sup.-doped KTaO.sub.3./sub..

0368463 - FZÚ 2012 RIV DE eng J - Journal Article
Trepakov, Vladimír - Skvortsov, A. - Poletaev, N. - Potůček, Zdeněk - Nuzhnyy, Dmitry - Jastrabík, Lubomír - Dejneka, Alexandr
An optical and dielectric spectroscopy study of Er³⁺-doped KTaO₃.
Physica Status Solidi B. Roč. 248, č. 12 (2011), s. 2908-2915. ISSN 0370-1972. E-ISSN 1521-3951
R&D Projects: GA ČR GC202/09/J017; GA AV ČR KAN301370701; GA MŠMT(CZ) 1M06002
Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100522
Keywords : Er³⁺ centres * IR spectroscopy * optical absorption photoluminescence * potassium tantalate * THz spectroscopy
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 1.316, year: 2011

We report the results of a multifaceted study of optical and dielectric properties of erbium-doped potassium tantalate crystals. Studies of optical absorption and photoluminescence allowed us to determine the system of energy levels that control the main internal optical transitions in the 4f electronic shell of Er3+ in KTaO3. It was found that at least two types of Er-centres,major and minor ones, are present. The major centres are noncubic,formed by Er3+ substituting for K+ sites; these are responsible for the n-type conductivity of crystals. Wideband optical absorption with a maximum at 1.13 eV was attributed to polaron formation.Far-IR reflectivity studies revealed an increase in the frequency of the lowest transverse optical mode and a decrease in the dielectric permittivity in comparison with undoped crystals. This stiffening means the suppression of the ferroelectric instability in the system.
Permanent Link: http://hdl.handle.net/11104/0202800