Role of high-order electromechanical coupling terms in thermodynamics of ferroelectric thin films

Currently used methods for the description of thermodynamics of ferroelectric thin films (Landau theory or ab initio based Monte Carlo simulations) are based on an energy expansion in terms of internal degrees of freedom. It was shown that these methods can suffer from a substantial inaccuracy unless higher order electromechanical interactions are taken into account. The high-order electromechanical couplings strongly renormalize the sixth-power polarization terms of the thermodynamic energy expansion. In this paper, apart from the general statement, we illustrate it with an example of a temperature-misfit strain phase diagram of a BaTiO3 thin film derived with high-order electromechanical interactions evaluated using first-principles calculations.


Published in:
Physical Review B, 87, 18, 184101
Year:
2013
Publisher:
College Pk, American Physical Society
ISSN:
1098-0121
Laboratories:




 Record created 2013-10-01, last modified 2018-03-17


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