Fig. 2: Defect analysis and atomic structure of DWs in pristine and quenched BiFeO3.
From: Domain-wall pinning and defect ordering in BiFeO3 probed on the atomic and nanoscale
HAADF-STEM image in [010] zone axis of a 109° DW in a pristine and b quenched BiFeO3 with corresponding c, d normalized distribution map of Bi-column intensities and average intensity profiles across the DW region; the values of ΔE between the O-K and Fe-L3 edges measured on and off the DW are also shown in the panels c, d; e, f average of Fe displacements determined from individual unit-cell rows and measured along [001] and [100] directions; g, h lattice-strain map represented in terms of lattice-distortion angle measured in [001] direction (ϕc). The DW region is indicated by a dashed red box. In panels (a,b) the arrows indicate the direction of the Fe displacements from the centre of the Bi sublattice; enlarged distances between the sheared Bi atoms columns (shear lattice strain) inside the DWs are indicated by red lines. Error bars in the intensity line profiles in panels c, d represent the standard deviation of the intensity measurements performed inside domain regions (~4% relative). Error bars in panels e, f represent the standard deviation of the displacement measurements across the DW.
