TY - JOUR
T1 - Stability of Polar Vortex Lattice in Ferroelectric Superlattices
JF - Nano Letters
Y1 - 2017/04//
SP - 2246
EP - 2252
A1 - Zijian Hong
A1 - Anoop R. Damodaran
A1 - Fei Xue
A1 - Shang-Lin Hsu
A1 - Jason Britson
A1 - Ajay K. Yadav
A1 - Christopher T. Nelson
A1 - Jian-Jun Wang
A1 - James F. Scott
A1 - Lane W. Martin
A1 - Ramamoorthy Ramesh
A1 - Long-Qing Chen
KW - Ferroelectric superlattices
KW - geometric length scale
KW - phase-field simulations
KW - topological structures by design
KW - ultrafine polar vortex
AB - A novel mesoscale state comprising of an ordered polar vortex lattice has been demonstrated in ferroelectric superlattices of PbTiO3/SrTiO3. Here, we employ phase-field simulations, analytical theory, and experimental observations to evaluate thermodynamic conditions and geometric length scales that are critical for the formation of such exotic vortex states. We show that the stability of these vortex lattices involves an intimate competition between long-range electrostatic, long-range elastic, and short-range polarization gradient-related interactions leading to both an upper and a lower bound to the length scale at which these states can be observed. We found that the critical length is related to the intrinsic domain wall width, which could serve as a simple intuitive design rule for the discovery of novel ultrafine topological structures in ferroic systems.
VL - 17
ER -