Mechanical Softness of Ferroelectric 180° Domain Walls

Christina Stefani,Eric Langenberg,Peng Chen,Neus Domingo,Darrell G Schlom,Sergey Artyukhin,Konstantin Shapovalov,Massimiliano Stengel,Gustau Catalan,Louis Ponet

doi:10.1103/physrevx.10.041001

Abstract

C. S. thanks BIST for the PREBIST Grant. This projecthas received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 754558. E. L. acknowledges the funding received from the European Union’s Horizon 2020 research and innovation program through the Marie Sklodowska-Curie Actions: Individual Fellowship-Global Fellowship (Ref. No. MSCA-IF-GF708129). M. S. and K. S. acknowledge the support of the European Research Council under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 724529), Ministerio de Economia, Industria y Competitividad through Grants No. MAT2016- 77100-C2-2-P and No. SEV-2015-0496, and the Generalitat de Catalunya (Grant No. 2017SGR 1506). G. C. acknowledge the support of the Ministerio de Economia, Industria y Competitividad, Agencia Estatal de Investigacion/Fondo Europeo de Desarrollo Regional and European Union through Grant No. MAT2016-77100-C2-1-P (MINECO/AEI/FEDER, UE).

Highlights

An important part of the appeal of domain walls resides in the functional contrast between their properties and those of the domains they separate
We measure the out-of-plane mechanical response of ferroelectric 180° domain walls and observe that, despite separating domains that are mechanically identical, the walls appear mechanically distinct—softer—compared to the domains. This effect is observed in different ferroelectric materials (LiNbO3, BaTiO3, and PbTiO3) and with different morphologies, suggesting that the effect is universal
Electrical conductance is measured in the ferroelectric domain walls PbðZr0.2Ti0.8ÞO3 [7], LiNbO3 [8], and BaTiO3, as well as those of multiferroic YMnO3 [9] and Cu3B7O13Cl [10]

Summary

INTRODUCTION

An important part of the appeal of domain walls resides in the functional contrast between their properties and those of the domains they separate. In contrast to the vigorous research on domain wall functionality, less is known about their mechanical properties Since ferroelectric 180° walls can be created or destroyed by voltage (by writing or erasing domains), this result suggests the possibility of using voltage to fabricate periodic and reconfigurable metamaterials with a regular pattern of internal elastic contrast Put another way, periodically poled ferroelectric crystals, which are already in use for photonic applications [32], may turn out to be phononic crystals

SAMPLES AND DOMAIN STRUCTURE

EXPERIMENTAL QUANTIFICATION OF DOMAIN WALL ELASTICITY

THEORY OF FERROELECTRIC DOMAIN WALL SOFTENING

Findings

CONCLUSIONS