Ferroelectricity Induced by a Combination of Crystallographic Chirality and Axial Vector.

Ferroelectric materials compatible with magnetism and/or conductive properties provide a platform for exploring unconventional phenomena, such as the magnetoelectric effect, nonreciprocal responses, and nontrivial superconductivity. Though recent studies on multiferroics have offered several approaches, the search for magnetic and/or conducting ferroelectric materials is still a challenging issue under the traditional "d-ness" rule, refusing active d electrons. Here, we propose the emergence of ferroelectricity through a combination of crystallographic chirality and axial vector, accepting even non-d magnetic ions.

Crystal structure and properties of perovskite-type rubidium niobate, a high-pressure phase of RbNbO.

We synthesized a perovskite-type RbNbO at 1173 K and 4 GPa from non-perovskite RbNbO and investigated its crystal structure and properties towards ferroelectric material design. Single-crystal X-ray diffraction analysis revealed an orthorhombic cell in the perovskite-type structure (space group 2, no. 38) with = 3.

Chemical design of a new displacive-type ferroelectric.

Since the discovery of the ferroelectric perovskite-type oxide BaTiO in 1943, numerous materials have been surveyed as candidates for new ferroelectrics. Perovskite-type materials have played a leading role in basic research and applications of ferroelectric materials since the last century. Experimentalists and theoreticians have developed a new materials design stream for post-perovskite materials.