Volume 106, Number 1, April 2014
|Number of page(s)||5|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||07 April 2014|
Giant increase of ferroelectric phase transition temperature in highly strained ferroelectric superlattice
1 Laboratoire de Physique de la Matière Condensée, Université de Picardie - 33 rue Saint-Leu, 80039 Amiens Cedex, France
2 Faculty of Physics, Southern Federal University - 5, Zorge str. Rostov-on-Don, 344090, Russia
Received: 18 March 2014
Accepted: 24 March 2014
We report epitaxial strain effects in the lead-free ferroelectric/paraelectric superlattice (SL) for a modulation period Λ of about 100 Å. We have demonstrated that the large strain in SL induces ferroelectricity in BaZrO3 layers, a material that is paraelectric at any temperature in the bulk form. The induced polar axis in BaZrO3 layers is perpendicular to the plane of the substrate while BaTiO3 layers exhibit in-plane polar orientation. Raman spectroscopy revealed a lattice ordering in SL due to the misfit strain generated by the large lattice mismatch between the alternating BaZrO3 and BaTiO3 layers. Such strain induces a huge upward frequency shift of the lowest E(1TO) soft mode from in the BaTiO3 single film to in the SL. The temperature of the ferroelectric phase transition in the SL was found to be upshifted by about with respect to the BaTiO3 single crystal.
PACS: 77.55.fe – BaTiO3-based films / 78.30.-j – Infrared and Raman spectra
© EPLA, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.