Unexpectedly high Curie temperature in weakly strained ferroelectric film

Anna G. Razumnaya (1, 2) , Alexey S. Mikheykin , Igor A. Lukyanchuk (1) , Vladimir B. Shirokov , Yury I. Golovko , Vladimir M. Mukhortov , Mimoun El Marssi (1) , Yury I. Yuzyuk

1 LPMC - Laboratoire de Physique de la Matière Condensée - UR UPJV 2081
2 Faculty of Physics

Polarized Raman spectra of the epitaxial Ba0.4Sr0.6TiO3 film grown on MgO substrate with thickness of 600nm were studied in a broad temperature range of 80-600K and the phase transition from paraelectric to tetragonal ferroelectric phase was observed at about 500K. This critical temperature is substantially higher than that calculated from the lattice-mismatch strain theory. In addition, the predicted from the theory low-temperature orthorhombic and rhombohedral phases were not observed. We ascribe the strengthening of the tetragonal ferroelectric phase to the effect of the interface-induced build-in electric field resulted from the interface-accumulated charges.

Domaines: Matière Condensée [cond-mat]

Anna G. Razumnaya, Alexey S. Mikheykin, Igor A. Lukyanchuk, Vladimir B. Shirokov, Yury I. Golovko, et al.. Unexpectedly high Curie temperature in weakly strained ferroelectric film. physica status solidi (b), 2017, 254 (4), ⟨10.1002/pssb.201600413⟩. ⟨hal-03627579⟩