Antiferroelectric materials are often cited as promising for energy storage applications. This is due to their electric-field induced phase transition to a polar phase and the associated response of polarization as a function of field P(E) that makes them more suitable than standard dielectrics. In practice, a very large body of published work revolve around a few end compounds with the perovskite structure both lead-based (PbZrO₃ and PbHfO₃) and lead-free (AgNbO₃ and NaNbO₃). The antiferroelectric character of these end compounds are basically known for decades even though they may not be understood in details because of the complexity of the microscopic mechanisms involved. From there, a lot of work uses chemical engineering to optimize properties for practical purposes. This involves in particular the tuning of the critical temperature and fields, and the reduction the hysteresis associated to losses.

In principle, it would be desirable to identify other families of compounds with different crystal structures in order to enrich this portofolio of potential antiferroelectrics. This is desirable both from a theoretical perspective, in order to better appreciate the variety of microscopic mechanisms responsible for antiferroelectricity, but also from application perspectives for a broader choice of end compounds. The search for new antiferroelectric materials however is impeded by a number of difficulties, starting with the somehow ambiguous definition of the notion itself. This includes also difficulties in identifying characteristic symmetry criterion or experimental signatures that could be used to screen efficiently large families of crystals. In this talk I will describe our theoretical and experimental approaches to this problem and our attempts to identify such signatures. This has led us to identify a unique example of a displacive antiferroelectric transition and explore the potential for antiferroelectricy in scheelites.