Threshold fields for antiparallel ferroelectric domain wall motion

TL;DR

This paper demonstrates through phase field modeling that broadening of antiparallel ferroelectric domain walls significantly reduces the electric field needed to move them, impacting ferroelectric device performance.

Contribution

It reveals that a slight increase in domain wall width dramatically lowers the threshold field for wall motion, a finding applicable to all ferroelectrics.

Findings

Threshold field drops by 2-3 orders of magnitude with ~2-3nm broadening.

Diffuse walls are more easily moved by electric fields.

Mechanism is applicable across all ferroelectric materials.

Abstract

While an ideal antiparallel ferroelectric wall is considered a unit cell in width (~0.5nm), we show using phase field modeling that the threshold field for moving this wall dramatically drops by 2-3 orders of magnitude if the wall were diffuse by only ~2-3nm. Since antiparallel domain walls are symmetry allowed in all ferroelectrics, and since domain wall broadening on nanometer scale is widely reported in literature, this mechanism is generally applicable to all ferroelectrics.