Antiferroelectricity in a family of pyroxene-like oxides with rich polymorphism

Abstract

AbstractAntiferroelectrics have potential applications in energy conversion and storage, but are scarce, particularly among oxides that otherwise display rich ferroic behaviours. A question then arises whether potential antiferroelectrics are being overlooked, simply because their corresponding ferroelectric phase has not been discovered yet. Here we report a first-principles study suggesting that this is the case for a family of ABO3 pyroxene-like materials, characterised by chains of corner-sharing BO4 tetrahedra, a well-known member being KVO3. The irregular tetrahedra have an electric dipole associated to them. In the most stable polymorph, the dipoles display an antipolar pattern with zero net moment. However, upon application of an electric field, half of the tetrahedra rotate, flipping the corresponding dipoles and reaching a ferroelectric state. We discuss the unique possibilities for tuning and optimisation of antiferroelectricity that these materials offer. We suggest that the structural features enabling this antiferroelectric behaviour can also be found in other all-important mineral families.