Preparation and Characterization of a High-Entropy Magnet, (Mg, Mn, Co, Ni, Cu)₃TeO₆

Abstract

Mg 0.6 Mn 0.7 Co 0.7 Ni 0.6 Cu 0.4 TeO 6 , which is isostructural with multiferroic Mn 3 TeO 6 (space group R 3). Study of its magnetic properties indicates establishment of the long-range antiferromagnetic order at 16.3 K, slightly lower than that of pure Mn 3 TeO 6 . The tiny hysteresis of magnetization loop along with specific heat data implies the presence of ferromagnetic magnons at low temperatures. Dielectric measurements reveal sequence of welldefined steps in the real part of permittivity and peaks in the imaginary parts of permittivity at 30, 92, and 212 K attributable to the highly diffused structural changes, which are characteristic to relaxor ferroelectrics. It is shown that usual interpretation of this structure type as corundum-related is not accurate: the hexagonal oxygen packing is not close and is not double-layered. Therefore, Mn 3 TeO 6 represents a very special structure type.