Multiferroism in Iron-Based Oxyfluoride Perovskites

Steven Hartman, Sung B. Cho, and Rohan Mishra.  Inorganic Chemistry 2018

Using first-principles density-functional theory (DFT) calculations, we predict that low-temperature fluorination of AA′Fe₂O₅(A = La³⁺, Y³⁺, Lu³⁺, Eu³⁺, In³⁺; A′ = Ca²⁺, Sr²⁺, Ba²⁺) oxygen-vacancy-ordered perovskites can produce room-temperature multiferroics. DFT calculations indicate that some of the resulting compounds should have robust antiferromagnetism as well as strong, switchable polarity from the hybrid improper mechanism. Furthermore, the magnitude of the spontaneous polarization can be controlled by changing the size ratio of the A and A′ cations.