Figure 5: Theoretical calculations of the domain shape.
From: Ionic field effect and memristive phenomena in single-point ferroelectric domain switching
(a) X-profile of the radial variation 
calculated at z=y=0, and room temperature LNO parameters ε11=84, ε33=39, Q31=−0.003 m4/C2, Q33=+0.016 m4/C2, q31=−0.216 N × 109 N × m2/C2, q33=+1.848 × 109 N × m2/C2, 
, α0=2.012 × 109 N × m2/C2,43 U=50 V, effective tip size a*=25 nm. (b) Angular dependence (polar plot) of the 180° DW energy density. Domain shape at different voltages U1<U2<U3<U4 in the system ‘ferroelectric/tip/dry air’ (c) and ‘ferroelectric /tip/water meniscus’ (d).
