title: Exploring topological defects in epitaxial BiFeO3 thin films.
abstract: Using a combination of piezoresponse force microscopy (PFM) and phase-field modeling, we demonstrate ubiquitous formation of center-type and possible ferroelectric closure domain arrangements during polarization switching near the ferroelastic domain walls in (100) oriented rhombohedral BiFeO(3). The formation of these topological defects is determined from the vertical and lateral PFM data and confirmed from the reversible changes in surface topography. These observations provide insight into the mechanisms of tip-induced ferroelastic domain control and suggest that formation of topological defect states under the action of local defect- and tip-induced fields is much more common than previously believed.
authors.affiliation: School of Materials Science and Engineering, University of New South Wales, Sydney 2052, Australia.
authors.forename: Rama K
authors.initials: RK
authors.lastname: Vasudevan
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chen
authors.forename: Hsiang-Hua
authors.initials: HH
authors.lastname: Tai
authors.forename: Nina
authors.initials: N
authors.lastname: Balke
authors.forename: Pingping
authors.initials: P
authors.lastname: Wu
authors.forename: Saswata
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: L Q
authors.initials: LQ
authors.lastname: Chen
authors.forename: Ying-Hao
authors.initials: YH
authors.lastname: Chu
authors.forename: I-Nan
authors.initials: IN
authors.lastname: Lin
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Kalinin
authors.forename: Valanoor
authors.initials: V
authors.lastname: Nagarajan