Faceting Oscillations in Nano-Ferroelectrics

TL;DR

This study reports on the periodic faceting oscillations of nano-sized ferroelectric disks under electron microscopy, revealing dynamic shape changes linked to defect interactions and similar to magnetic domain behaviors.

Contribution

It is the first to observe and analyze oscillating faceting behavior in nano-ferroelectrics under electron beam exposure.

Findings

Faceting oscillations occur every 10 seconds in PZT disks.

Oscillations involve transitions between circular and hexagonal shapes.

Behavior is analogous to magnetic domain wall oscillations.

Abstract

We observe periodic faceting of 8-nm diameter ferroelectric disks on a 10 s time-scale when thin Pb(Zr0.52Ti0.48)O3 (PZT) film is exposed to constant high-resolution transmission electron microscopy (HRTEM) beams. The oscillation is between circular disk geometry and sharply faceted hexagons. The behavior is analogous to that of spin structure and magnetic domain wall velocity oscillations in permalloy [A. Bisig et al., Nature Commun. 4, 2328 (2013)], involving overshoot and de-pinning from defects [C. P. Amann, et al., J. Rheol. 57, 149-175 (2013)].