Faceting Oscillations in Nano-Ferroelectrics
  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)]. 
J. F. Scott and Ashok Kumar
cond-mat.mtrl-sci