The Rational Design of New Antiferroelectrics and Ferroelectrics

Developing new families of functional materials requires the incorporation of rational design principles. Highlighted here is a rational design strategy that combines the results of first-principles calculations, systematic phase transitions searches, and crystallographic database mining techniques to create new antiferroelectric and ferroelectric oxides and chalcogenides. Our work explores a candidate family of materials with a general formula of <i>A</i>₂<i>BX</i>₃, where some, but not all, members have previously been synthesized but their functional properties have not yet been fully characterized. We use density functional theory to map out the potential energy landscape of this family by including both known and as-yet to be identified structure types to understand how atomistic composition would affect measurable properties and influence functionality. For the antiferroelectric compounds, we assess the dynamic stability of both the computed antipolar ground state and metastable polar state through a complete vibrational mode analysis, which includes the dielectric response. The results of our rational design scheme is a targeted set of oxide and chalcogenide semiconductors, and their compositionally tuned variants, that warrant synthesis and further investigation as new functional materials.