On the possibility that PbZrO$_3$ not be antiferroelectric

TL;DR

This paper proposes that PbZrO$_3$ may not be truly antiferroelectric but instead ferrielectric, based on first-principles calculations showing a more stable ferrielectric phase at low temperatures, challenging traditional understanding.

Contribution

It introduces a simple ferrielectric structure for PbZrO$_3$ and demonstrates its stability over the antiferroelectric phase through first-principles calculations.

Findings

Ferrielectric phase more stable than antiferroelectric phase at low temperatures.

PbZrO$_3$ may not be antiferroelectric at ambient conditions.

Implications for experimental interpretation and phase realization.

Abstract

Lead zirconate (PbZrO$_3$) is considered the prototypical antiferroelectric material with an antipolar ground state. Yet, several experimental and theoretical works hint at a partially polar behaviour in this compound, indicating that the polarization may not be completely compensated. In this work we propose a simple ferrielectric structure for lead zirconate. First-principles calculations reveal this state to be more stable than the commonly accepted antiferroelectric phase at low temperatures, possibly up to room temperature, suggesting that PbZrO$_3$ may not be antiferroelectric at ambient conditions. We discuss the implications of our discovery, how it can be reconciled with experimental observations and how the ferrielectric phase could be obtained in practice.