Domain-Wall Conduction Model for the Lateral Expansion of Ferroelectric Domains Inverted by Force-Microscope Tips

Ferroelectric domain inversion by nano-scale tips of atomic-force microscopes shows a strong $$\mu $$ m-sized lateral domain expansion upon application of voltage pulses. We propose a simple self-consistent physical model of this phenomenon based on the concept of domain-wall conduction. The model is capable of a quantitative explanation of a large body of experimental data relevant to lithium niobate crystals. It provides not only the necessary charge compensation far from the tip, but also the absence of the known electrostatic field singularities at the domain edges.