2007/05/31 by P. Zubko, Pavlo Zubko, G. Catalan +4 · 9 citations
Materials Science · Physics and Astronomy · #Ferroelectric and Piezoelectric Materials #Multiferroics and related materials #Nonlocal and gradient elasticity in micro/nano structures #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.99.167601
published as Phys. Rev. Lett. 99, 167601 (2007) · 4 pages, 3 figures, 1 table
openalex publication_date 2007/10/19 · arxiv created 2007/10/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Piezoelectricity is inherent only in noncentrosymmetric materials, but a piezoelectric response can also be obtained in centrosymmetric crystals if subjected to inhomogeneous deformation. This phenomenon, known as flexoelectricity, can significantly affect the functional properties of insulators, particularly thin films of high permittivity materials. We have measured strain-gradient-induced polarization in single crystals of paraelectric SrTiO3 as a function of temperature and orientation down to and below the 105 K phase transition. Estimates were obtained for all the components of the flexoelectric tensor, and calculations based on these indicate that local polarization around defects in SrTiO3 may exceed the largest ferroelectric polarizations. A sign reversal of the flexoelectric response detected below the phase transition suggests that the ferroelastic domain walls of SrTiO3 may be polar.