Preparation and Properties of a High-Entropy Wolframite-Type Antiferromagnet, (MnCoNiCuCd)WO.

The homogeneous high-entropy wolframite-type solid solution (MnCoNiCuCd)WO was prepared by solid-state reaction at 1000 °C. Elongated "crystals" were grown from the NaWO flux, but their strongly broadened powder X-ray diffraction patterns indicated partial dissolution. Nevertheless, successive annealing of the homogeneous solid solution for 3-4 h at 800, 700, and 600 °C did not bring any sign of dissolution. Thus, the material is kinetically stable at low temperatures although thermodynamically unstable. The long-range antiferromagnetic order was established at ∼ 24.8 K. Based on magnetization and specific heat measurements, a magnetic phase diagram was built, demonstrating the presence of an additional field-induced phase. In contrast to the parent MnWO, no dielectric anomaly has been found down to 2 K.