Mn${}_2$FeSbO${}_6$: a ferrimagnetic ilmenite and an antiferromagnetic perovskite

Due of its polymorphism, Mn${}_2$FeSbO${}_6$ can be synthesized at high pressures and temperatures as a ferrimagnetic ilmenite or an antiferromagnetic perovskite. The structural phase transformation is discussed in detail, and magnetic structures are proposed for both phases. The high-pressure Mn${}_2$FeSbO${}_6$ polymorph is a rare example of $A_2{B}^{\mathrm{\prime }}B\mathrm{"}$O${}_6$ perovskite with solely Mn cations on the $A$-site. Fe and Sb cations are ordered on the $B$-sites. Theoretical calculations for the perovskite phase suggest a complex magnetic structure, holding an electronic polarization.