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arXiv · cond-mat/9907391

Polarization Instability in Polydomain Ferroelectric Epitaxial Thin Films and the Formation of Heterophase Structures

Abstract

A thermodynamic theory is developed for dense laminar domain structures in epitaxial ferrolectric films. It is found that, at some critical misfit strain between the film and substrate, the 90 degrees c/a/c/a domain structure becomes unstable with respect to the appearance of the polarization component parallel to domain walls, which results in the formation of a heterophase structure. For PbTiO_3 and BaTiO_3 films, the stability ranges of polydomain and heterophase states are determined using "misfit strain - temperature" diagrams. Dielectric anomalies accompanying misfit-strain-driven structural transformations are described.

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BibTeXRIS

N. A. Pertsev, V. G. Koukhar. 1999-07-26. Polarization Instability in Polydomain Ferroelectric Epitaxial Thin Films and the Formation of Heterophase Structures. https://doi.org/10.1103/physrevlett.84.3722

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