Manipulation of BiFeO3 nanostructure by substrate terrace morphology.

[Display omitted] • BiFeO 3 nanostructure can be modulated by substrate terrace morphology. • Wide and straight terrace favor the step-flow growth mode and nano-stripe structure formation. • Nano-maze structure and nanoisland structure perfer to grow on bunched terrace and narrow/rough terrace, respectively. • Tail-to-tail domain wall with enhanced conduction formed on nano-stripe structure. Topological domain structures, such as vortex and center domain have been found in BiFeO 3 nanoislands fabricated by self-assemble approaches, which exhibit great application potential in nonvolatile storage. However, how to control the self-assembled nanostructure during preparation process is still an open question. Here, we successfully grew BiFeO 3 films with nano-stripe, nano-maze and dense nanoisland structures on LaAlO 3 (0 0 1) substrate by pulsed laser deposition. We found the formation of different nanostructures is related to the terrace morphology of the substrate. Nano-stripe structure with strip domain and high conduction tail-to-tail domain wall preferred to form on wide terrace, nano-maze structure with three-fold or four-fold center-type domain usually form on bunched terrace, while dense nanoisland structure with two/three-fold domain preferred to from on the narrow or rough terrace LaAlO 3 substrate. These findings provide guidance for manipulating the ferroelectric topological domain structure during film preparation process. [ABSTRACT FROM AUTHOR]