Evidence for strain-induced ferroelectric order in epitaxial thin-film KTaO.sub.3./sub..

0347559 - FZÚ 2011 RIV US eng J - Journal Article
Tyunina, M. - Narkilahti, J. - Plekh, M. - Oja, R. - Nieminen, R.M. - Dejneka, Alexandr - Trepakov, Vladimír
Evidence for strain-induced ferroelectric order in epitaxial thin-film KTaO₃.
Physical Review Letters. Roč. 104, č. 22 (2010), 227601/1-227601/4. ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA AV ČR KAN301370701
Institutional research plan: CEZ:AV0Z10100522
Keywords : strain-induced ferroelectric order * KTaO₃ film
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 7.621, year: 2010

In perovskite-structure epitaxial films, it has been theoretically predicted that the polarization and the coherence of polar order can increase with increasing crystallographic strain. Experimental evidence of strain-induced long-range ferroelectric order has not been obtained thus far, posing the fundamental question of whether or not strain can induce the long-range polar order. Here we demonstrate the existence of strain-induced ferroelectric order in quantum paraelectric KTaO3 by combining experimental investigations of epitaxial KTaO3 films and density-functional-theory calculations. The long-range ferroelectric order does exist under a large enough epitaxial strain. We suggest that a region of short-range polar order might appear between paraelectric and ferroelectric states in the strain-temperature phase diagrams.
Permanent Link: http://hdl.handle.net/11104/0188315