High tunability of the soft mode in strained SrTiO(3)/DyScO(3) multilayers.
J Phys Condens Matter
; 21(11): 115902, 2009 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-21693932
ABSTRACT
SrTiO(3)/DyScO(3) epitaxial multilayers with variable number and thickness (10-100 nm) of bilayers deposited on DyScO(3) substrates were investigated by means of time-domain terahertz spectroscopy at room temperature. A tensile strain develops in the SrTiO(3) films and shifts the eigenfrequency of the ferroelectric soft mode down by â¼25-45 cm(-1) with respect to the value found for single crystals. In all films the soft mode strongly hardens upon the electrical bias and a linear coupling to a silent excitation of relaxation type at 10 cm(-1) is observed. We show that the change in the THz and sub-THz response of the layers with an increasing field is determined solely by the soft mode eigenfrequency and we propose a phenomenological model describing the origin of the tunability and the peculiar properties of the ferroelectric soft mode in the terahertz spectral range.
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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
/
Qualitative_research
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article