Ferroelectric phase transitions in ultrathin films of BaTiO3

Paul, Jaita ; Nishimatsu, Takeshi ; Kawazoe, Yoshiyuki ; Waghmare, Umesh V. (2007) Ferroelectric phase transitions in ultrathin films of BaTiO3 Physical Review Letters, 99 (7). 077601_1-077601_4. ISSN 0031-9007

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Official URL: http://prl.aps.org/abstract/PRL/v99/i7/e077601

Related URL: http://dx.doi.org/10.1103/PhysRevLett.99.077601

Abstract

We present molecular dynamics simulations of a realistic model of an ultrathin film of BaTiO3 sandwiched between short-circuited electrodes to determine and understand effects of film thickness, epitaxial strain, and the nature of electrodes on its ferroelectric phase transitions as a function of temperature. We determine a full epitaxial strain-temperature phase diagram in the presence of perfect electrodes. Even with the vanishing depolarization field, we find that ferroelectric phase transitions to states with in-plane and out-of-plane components of polarization exhibit dependence on thickness; it arises from the interactions of local dipoles with their electrostatic images in the presence of electrodes. Secondly, in the presence of relatively bad metal electrodes which only partly compensate the surface charges and depolarization field, a qualitatively different phase with stripelike domains is stabilized at low temperature.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:59387
Deposited On:06 Sep 2011 05:31
Last Modified:18 May 2016 09:58

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