%0 Journal Article
%K Transmission electron microscopy
%K Perovskite
%K Electrons
%K Oxygen
%K Heterostructures
%K Polarization
%K Domain walls
%K Ferroelectric materials
%K Principal component analysis
%K Ferroelectricity
%K Bismuth ferrite
%K Structural order parameter
%K Scanning transmission electron microscopy
%K Bismuth
%K Ferrite
%K Scanning
%K Atomic columns
%K Charged domain wall
%K Competing orders
%K Ferroelectric domain walls
%K Ginzburg Landau theory
%K Phase-contrast imaging
%K Precise analysis
%K Principal Components
%K Relative contribution
%K Shape analysis
%K Wall energy
%K Z-contrast scanning
%A A.Y Borisevich
%A O.S Ovchinnikov
%A H.J Chang
%A M.P Oxley
%A P Yu
%A J Seidel
%A E.A Eliseev
%A A.N Morozovska
%A Ramamoorthy Ramesh
%A S.J Pennycook
%A S.V Kalinin
%B ACS Nano
%D 2010
%G eng
%P 6071-6079
%R 10.1021/nn1011539
%T Mapping octahedral tilts and polarization across a domain wall in BiFeO3 from Z-contrast scanning transmission electron microscopy image atomic column shape analysis
%V 4
%X Oxygen octahedral tilts underpin the functionality of a large number of perovskite-based materials and heterostructures with competing order parameters. We show how a precise analysis of atomic column shapes in Z-contrast scanning transmission electron microscopy images can reveal polarization and octahedral tilt behavior across uncharged and charged domain walls in BiFeO3. This method is capable of visualizing octahedral tilts to much higher thicknesses than phase contrast imaging. We find that the octahedral tilt transition across a charged domain wall is atomically abrupt, while the associated polarization profile is diffuse (1.5-2 nm). Ginzburg-Landau theory then allows the relative contributions of polarization and the structural order parameters to the wall energy to be determined. © 2010 American Chemical Society.