Magnetic order near 270 K in mineral and synthetic Mn₂FeSbO₆ ilmenite

The structural and magnetic properties of Mn$_2$FeSbO$_6$ single-crystalline mineral and ceramic samples synthesized under thermobaric treatment have been investigated, and compared to theoretical predictions based on first-principles electronic structure calculations. This ilmenite system displays a sharp magnetic transition just below the room temperature related to a ferrimagnetic ordering of the Mn$^{2+}$ and Fe$^{3+}$ cations, which makes Mn$_2$FeSbO$_6$ a promising candidate for designing functional magnetic materials.