A first-principles study of phase transitions in ultrathin films of BaTiO3

Paul, J. ; Nishimatsu, T. ; Kawazoe, Y. ; Waghmare, U. V. (2008) A first-principles study of phase transitions in ultrathin films of BaTiO3 Pramana - Journal of Physics, 70 (2). pp. 263-270. ISSN 0304-4289

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Official URL: http://www.ias.ac.in/pramana/v70/p263/abs.htm

Related URL: http://dx.doi.org/10.1007/s12043-008-0045-9

Abstract

We determine the effects of film thickness, epitaxial strain and the nature of electrodes on ferroelectric phase transitions in ultrathin films of BaTiO3 using a first-principles effective Hamiltonian in classical molecular dynamics simulations. We present results for polarization and dielectric properties as a function of temperature and epitaxial strain, leading to size-dependent temperature-strain phase diagram for the films sandwiched between 'perfect' electrodes. In the presence of non-vanishing depolarization fields when non-ideal electrodes are used, we show that a stable stripe-domain phase is obtained at low temperatures. The electrostatic images in the presence of electrodes and their interaction with local dipoles in the film explain these observed phenomena.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Ferroelectric Phase Transition; Polarization; Epitaxial Strain; Electrodes
ID Code:59370
Deposited On:06 Sep 2011 05:32
Last Modified:18 May 2016 09:58

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