title: Domain wall geometry controls conduction in ferroelectrics.
abstract: A new paradigm of domain wall nanoelectronics has emerged recently, in which the domain wall in a ferroic is itself an active device element. The ability to spatially modulate the ferroic order parameter within a single domain wall allows the physical properties to be tailored at will and hence opens vastly unexplored device possibilities. Here, we demonstrate via ambient and ultrahigh-vacuum (UHV) scanning probe microscopy (SPM) measurements in bismuth ferrite that the conductivity of the domain walls can be modulated by up to 500% in the spatial dimension as a function of domain wall curvature. Landau-Ginzburg-Devonshire calculations reveal the conduction is a result of carriers or vacancies migrating to neutralize the charge at the formed interface. Phase-field modeling indicates that anisotropic potential distributions can occur even for initially uncharged walls, from polarization dynamics mediated by elastic effects. These results are the first proof of concept for modulation of charge as a function of domain wall geometry by a proximal probe, thereby expanding potential applications for oxide ferroics in future nanoscale electronics.
authors.affiliation: School of Materials Science and Engineering, University of New South Wales, Kensington 2052, Australia.
authors.forename: R K
authors.initials: RK
authors.lastname: Vasudevan
authors.forename: A N
authors.initials: AN
authors.lastname: Morozovska
authors.forename: E A
authors.initials: EA
authors.lastname: Eliseev
authors.forename: J
authors.initials: J
authors.lastname: Britson
authors.forename: J-C
authors.initials: JC
authors.lastname: Yang
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chu
authors.forename: P
authors.initials: P
authors.lastname: Maksymovych
authors.forename: L Q
authors.initials: LQ
authors.lastname: Chen
authors.forename: V
authors.initials: V
authors.lastname: Nagarajan
authors.forename: S V
authors.initials: SV
authors.lastname: Kalinin
mesh_terms: D016880:Anisotropy; D004548:Elasticity; D004553:Electric Conductivity; D004560:Electricity; D004581:Electronics; D007477:Ions; D007700:Kinetics; D018625:Microscopy, Atomic Force / Q000379:methods; D020527:Microscopy, Scanning Probe / Q000379:methods; D015233:Models, Statistical; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D012666:Semiconductors; D013816:Thermodynamics
chemical_list: D007477:Ions; D010087:Oxides; D010100:Oxygen