0386395 - FZÚ 2015 RIV US eng J - Journal Article
Tyunina, Marina - Dejneka, Alexandr - Chvostová, Dagmar - Levoska, J. - Plekh, M. - Jastrabík, Lubomír
Phase transitions in ferroelectric Pb_0.5Sr_0.5TiO₃ films probed by spectroscopic ellipsometry.
Physical Review. B. Roč. 86, č. 22 (2012), "224105-1"-"224105-6". ISSN 1098-0121. E-ISSN 2469-9969
R&D Projects: GA TA ČR TA01010517; GA ČR GAP108/12/1941
Institutional research plan: CEZ:AV0Z10100522
Keywords : Pb_0.5Sr_0.5TiO₃ fthin films * spectroscopic ellipsometry * phase transitions
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.767, year: 2012

Phase transitions occurring in Pb0.5Sr0.5TiO3 films are experimentally studied by combining spectroscopic ellipsometry and low-frequency dielectric analysis. Polycrystalline and polydomain epitaxial films with relaxedmisfit strain and columnarmicrostructure are investigated. The paraelectric and the ferroelectric states, and the temperatures and widths of the paraelectric-to-ferroelectric phase transitions, are identified from the temperature evolution of refractive index measured in transparency range. The temperatures at which transitions start on cooling are found to be considerably higher than the temperatures of the dielectric peaks. In contrast to the broad dielectric peaks, the transition width of 60 K in the polycrystalline film and that of 20 K in the polydomain epitaxial film are revealed. The discrepancies between optical and dielectric data are explained by the influence of extrinsic factors on the low-frequency response.
Permanent Link: http://hdl.handle.net/11104/0215690