Magnetic‐Structure‐Stabilized Polarization in an Above‐Room‐Temperature Ferrimagnet

Abstract

Abstract Above‐room‐temperature polar magnets are of interest due to their practical applications in spintronics. Here we present a strategy to design high‐temperature polar magnetic oxides in the corundum‐derived A 2 BB′O 6 family, exemplified by the non‐centrosymmetric ( R 3) Ni 3 TeO 6 ‐type Mn 2+ 2 Fe 3+ Mo 5+ O 6 , which shows strong ferrimagnetic ordering with T C =337 K and demonstrates structural polarization without any ions with ( n −1)d 10 n s 0 , d 0 , or stereoactive lone‐pair electrons. Density functional theory calculations confirm the experimental results and suggest that the energy of the magnetically ordered structure, based on the Ni 3 TeO 6 prototype, is significantly lower than that of any related structure, and accounts for the spontaneous polarization (68 μC cm −2 ) and non‐centrosymmetry confirmed directly by second harmonic generation. These results motivate new directions in the search for practical magnetoelectric/multiferroic materials.