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arXiv · 1201.5085

Surface polar states and pyroelectricity in ferroelastics induced by flexo-roto field

A. N. Morozovska·E. A. Eliseev·S. V. Kalinin·Long Qing Chen·Venkatraman Gopalan
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Abstract

Theoretical analysis based on the Landau-Ginzburg-Devonshire (LGD) theory is used to show that the joint action of flexoelectric effect and rotostriction leads to a large spontaneous in-plane polarization (~ 1-5 muC/cm2) and pyroelectric coefficient (~10^-3 C/m2K) in the vicinity of surfaces of otherwise non-ferroelectric ferroelastics, such as SrTiO3, with static octahedral rotations. The origin of the improper polarization and pyroelectricity is an electric field we name flexo-roto field whose strength is proportional to the convolution of the flexoelectric and rotostriction tensors with octahedral tilts and their gradients. Flexo-roto field should exist at surfaces and interfaces in all structures with static octahedral rotations, and thus it can induce surface polar states and pyroelectricity in a large class of otherwise nonpolar materials.

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A. N. Morozovska, E. A. Eliseev, S. V. Kalinin, Long Qing Chen, Venkatraman Gopalan. 2012-01-24. Surface polar states and pyroelectricity in ferroelastics induced by flexo-roto field. https://doi.org/10.1063/1.3701152

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