There are ample experimental evidences indicating that the ferroelastic domain walls of incipient ferroelectrics, such as SrTiO3 and CaTiO3, are polar. The emergence of such interfacial polar order at a domain wall is exciting and believed to arise from the coupling between a primary order parameter, such as a strain or an antiferrodistortive (AFD) order parameter, and polarization. There have been several mechanisms proposed to explain the emergence of interfacial polar order, including biquadratic coupling, AFD-antiferroelectric coupling, and flexoelectric coupling. Using CaTiO3 as an example, we demonstrate, using both asymptotic analytics and numerical calculation, that the flexoelectric coupling is likely the dominant mechanism leading to the interfacial polar order.
Y. Gu et al., "Origin of Interfacial Polar Order in Incipient Ferroelectrics," Physical Review B - Condensed Matter and Materials Physics, vol. 91, no. 17, American Physical Society (APS), May 2015.
The definitive version is available at https://doi.org/10.1103/PhysRevB.91.174103
Materials Science and Engineering
Keywords and Phrases
Ferroelectric materials; Ferroelectricity; Ferroelectric tunnel
International Standard Serial Number (ISSN)
Article - Journal
© 2015 American Physical Society (APS), All rights reserved.
01 May 2015
This paper was supported by the National Science Foundation (NSF) through Grants No. DMR-1410714, No. DMR-1210588, and No. DMR 1234096.