Correlation Between Structure And C-Afm Contrast Of 180-Degree Domain Walls In Rhombohedral Bati03

Abstract

Using Landau-Ginzburg-Devonshire theory we describe 180-degree domain wall structure, intrinsic energy and carrier accumulation in rhombohedral phase of BaTiO3 as a function of the wall orientation and flexoelectric coupling strength. Two types of domain wall structures (phases of the wall) exist depending on the wall orientation. The low-energy 'achiral' phase occurs in the vicinity of the {110} wall orientation and has odd polarization profile invariant with respect to inversion about the wall center. The second 'chiral' phase occurs around {211} wall orientations and corresponds to mixed parity domain walls that may be of left-handed or right-handed chirality. The transformation between the phases is abrupt, accompanied with 20-30% change of the domain wall thickness and can happen at fixed wall orientation with temperature change. We suggest that the phase transition may be detected through domain wall thickness change or by c-AFM. The structure of the domain wall is correlated to its conductivity through polarization component normal to the domain wall, which causes free carriers accumulation. Depending on the temperature and flexoelectric coupling strength relative conductivity of the wall becomes at least one order of magnitude higher than in the single-domain region, creating c-AFM contrast enhancement pronounced and detectable.

31 pages, 10 figures, Supplementary materials

References in corpus (3)

• Conduction at domain walls in insulating Pb(Zr${}_{0.2}$Ti${}_{0.8}$)O${}_3$ thin films
• Understanding the origins of the intrinsic dead-layer effect in nanocapacitors
• Bloch-type Domain Walls in Rhombohedral BaTiO3

Cited by in corpus (7)

• Defect driven flexo-chemical coupling in thin ferroelectric films
• Chiral Polarization Textures Induced by the Flexoelectric Effect in Ferroelectric Nanocylinders
• Flexo-Sensitive Polarization Vortices in Thin Ferroelectric Films
• From bulk descriptions to emergent interfaces: connecting the Ginzburg-Landau and elastic line models
• Non-Ising domain walls in c-phase ferroelectric lead titanate thin films
• Flexocoupling impact on the kinetics of polarization reversal
• Flexoelectricity induced spatially modulated phases in ferroics and liquid crystals (Author review)