Spectroscopic ellipsometry of SrTiO.sub.3./sub. crystals applied to antiferrodistortive surface phase transition

0347971 - FZÚ 2011 RIV DE eng J - Journal Article
Dejneka, Alexandr - Trepakov, Vladimír - Jastrabík, Lubomír
Spectroscopic ellipsometry of SrTiO₃ crystals applied to antiferrodistortive surface phase transition.
Physica Status Solidi B. Roč. 247, č. 8 (2010), s. 1951-1955. ISSN 0370-1972. E-ISSN 1521-3951
R&D Projects: GA ČR GC202/09/J017; GA ČR GA202/08/1009; GA AV ČR KAN301370701; GA MŠMT(CZ) 1M06002
Institutional research plan: CEZ:AV0Z10100522
Keywords : ellipsometry * optical properties * phase transitions * surfaces and interfaces
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.344, year: 2010

This work is devoted to the ellipsometric study of antiferrodistortive cubic-to-tetragonal phase transition (PT) of SrTiO3 surface. Strong influence of surface defect structure on magnitude and temperature evolutions of surface refractive index related to PT was found and investigated. It is shown that even small surface imperfections result in enhancement and strong changes of the surface refractive index when approaching the temperature of PT. This effect is caused by emergence and evolutions in the surface of the structural changes corresponding to order parameter at the temperatures sufficiently higher than transition temperature in the bulk. In the case of structurally perfect crystal surface, the features of the temperature dependence of surface refractive index appeared to be very small and visible at the temperatures a little smaller than transition temperature for bulk that agrees well with predictions of Kaganov–Omel’yanchuk theory.
Permanent Link: http://hdl.handle.net/11104/0188607