Ferroelectric and antiferroelectric materials have been widely studied in recent decades due to their unusual electrical behaviour. In these systems, electric dipoles spontaneously arrange themselves in an ordered way throughout a crystal. An electric dipole is a small separation between positive and negative charges at the atomic or molecular scale. In ferroelectric materials, these dipoles point in the same direction, producing an overall electrical polarisation in the material. In antiferroelectrics, however, the dipoles point in opposite directions and cancel each other out, so the material has no overall polarisation. When an external electric field is applied, however, the dipoles can reorient themselves and the material can switch to a polarised state. This ability to change state makes such materials particularly useful for applications including energy storage, electronics, and cooling technologies.

Despite this commonly accepted definition, a new perspective article published in Nature Materials suggests that the way these materials are traditionally classified should be reconsidered. This international collaboration, involving ICREA Prof. Gustau Catalan (leader of the ICN2 Oxide Nanophysics Group), reveals that many antiferroelectric systems exhibit configurations more complex than previously thought. Rather than showing a simple, alternating pattern of opposite dipoles, some materials show hybrid structures or non-collinear arrangements, with different types of electrical order. Additionally, composites can be engineered to have no antiparallel arrangements of dipoles but still be able to jump into a polar state under an external voltage. Such materials, called “synthetic antiferroelectrics”, do not fit under the traditional definition of antiferroelectrics.

According to the researchers, a broader view is needed to accommodate the variety of experimental results reported in antiferroelectric and antiferroelectric-like materials in recent years. The Perspective article proposes an expanded conceptual framework with which to describe these phenomena. The authors argue that antiferroelectric behaviour does not depend solely on a perfectly alternating arrangement of dipoles. It can also be present in more complex charge patterns. The article also discusses the emergence of topological structures (vortices, antivortices, antiphase boundaries and so forth) which are singular -but very robust- dipolar arrangements distinct from the rest of the material.  A better understanding of these structures could help researchers to design materials with tunable properties, more efficient electronic devices and advanced energy storage systems.

Reference article:

Catalan, G; Gruverman, A; Íñiguez‑González, J; Meier, D; Trassin, MA; A modern perspective on antiferroelectrics. Nature Materials. (2026). https://doi.org/10.1038/s41563-026-02483-z