Prediction of Room Temperature Electric Field Reversal of Magnetization in the Family of A_{4}B_{3}O_{9} Layered...

The promise of a strong magnetoelectric coupling in a multiferroic material is not only of fundamental interest, but also forms the basis of next generation memory devices where the direction of magnetization can be reversed by an external electric field. Using group-theory led first-principles calculations, we have identified a hitherto unknown polar phase of the A_{4}B_{3}O_{9} layered oxides, where the polar mode couples to the magnetic modes through a rare Γ-point magnetoelectric-multiferroic coupling scheme such that the net magnetization can be directly reversed by an electric field switching of the polar mode. Furthermore, in agreement with previous experimental observations, we predict room temperature magnetism in A_{4}B_{3}O_{9} oxides that indicates the promising practical applications of these compounds in the next generation memory devices.