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

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.

16 pages, 3 figures, 1 table, supplementary materials

References in corpus (7)

• Strain gradient induced polarization in SrTiO3 single crystals
• First-principles theory of frozen-ion flexoelectricity
• Interfacial Polarization and Pyroelectricity in Antiferrodistortive Structures Induced by a Flexoelectric Effect and Rotostriction
• New Symmetries in Crystals and Handed Structures
• Room temperature surface piezoelectricity in SrTiO3 ceramics via piezoresponse force microscopy
• Surface polar states and pyroelectricity in ferroelastics induced by flexo-roto field
• Manifestations of Broken Symmetry: The Surface Phases of Ca(2-x)Sr(x)RuO4

Cited by in corpus (11)

• Breaking of macroscopic centric symmetry in paraelectric phases of ferroelectric materials and implications for flexoelectricity
• Flexoelectricity from density-functional perturbation theory
• Conductivity of twin walls - surface junctions in ferroelastics: interplay of deformation potential, octahedral rotations, improper ferroelectricity and flexoelectric coupling
• Surface polar states and pyroelectricity in ferroelastics induced by flexo-roto field
• Defect thermodynamics and kinetics in thin strained ferroelectric films: the interplay of possible mechanisms
• New multiferroics based on EuxSr1-xTiO3 nanotubes and nanowires
• Roto-flexoelectric coupling impact on the phase diagrams and pyroelectricity of thin SrTiO3 films
• Low-symmetry monoclinic phase stabilized by oxygen octahedra rotations in thin strained EuxSr1-xTiO3 films
• Rotomagnetic couplings influence on the magnetic properties of antiferrodistortive antiferromagnets
• Flexocoupling impact on the kinetics of polarization reversal
• Intrinsic structural instabilities of domain walls driven by gradient couplings: meandering anferrodistortive-ferroelectric domain walls in BiFeO3