# Origin of sawtooth domain walls in ferroelectrics

## TL;DR

This paper investigates the origin of sawtooth-shaped domain walls in ferroelectric materials like BiFeO3 and PbTiO3, revealing that the interplay between Coulomb and short-range interactions causes their formation and influences their periodicity.

## Contribution

A minimal model combined with Monte-Carlo simulations explains the formation and periodicity of sawtooth domain walls in ferroelectrics, highlighting the role of competing interactions.

## Key findings

- Competition between Coulomb and short-range interactions causes sawtooth domain walls.
- Relative strength of interactions determines the periodicity of the domain walls.
- Conditions for the formation of such domain walls are identified.

## Abstract

Domains and domain walls are among the key factors that determine the performance of ferroelectric materials. In recent years, a unique type of domain walls, i.e., the sawtooth-shaped domain walls, has been observed in BiFeO$_{3}$ and PbTiO$_{3}$. Here, we build a minimal model to reveal the origin of these sawtooth-shaped domain walls. Incorporating this model into Monte-Carlo simulations shows that (i) the competition between the long-range Coulomb interaction (due to bound charges) and short-range interaction (due to opposite dipoles) is responsible for the formation of these peculiar domain walls and (ii) their relative strength is critical in determining the periodicity of these sawtooth-shaped domain walls. Necessary conditions to form such domain walls are also discussed.