Ferroelectric 180u000b0; a-a nanostripe and nanoneedle domains in thin BaTiO3 films prepared with focused-ion beam

摘要

Ferroelectric 180u000b0; a-a nanostripe domain structure was observed by transmission electron microscopy in a thin (ʧD;100 nm) film prepared from a bulk single crystal of BaTiO3 with focused-ion beam (FIB). The domain consists of alternate sequences of narrow and wide anti-parallel domains. High-magnification images of a stable 180u000b0; nanoneedle domain, with a sharp tip penetrating into the nanostripe domains, were also obtained. Two-dimensional phase-field simulations based on time-dependent GinzburgߝLandau (TDGL) equations suggest a possibility that such a domain structure is created and stabilized by an in-plane anisotropic stress and an anisotropic mechanical boundary condition of the thin film prepared with FIB.