Flash assisted synthesis and densification of five component high entropy oxide (Mg, Co, Cu, Ni, Zn)O at 350 °C in 3 min

Abstract

Five-component high entropy oxides oxide (Zn, Cu, Co, Ni, Mg)O generally requires annealing at temperatures greater than 850 °C (for several hours) for entropic stabilization of rocksalt solid solution phase. Flash assisted synthesis/stabilization and densification was carried out at a much lower furnace temperature of 350 °C for 3 min. to form nanocrystalline phase-pure rocksalt solid solution. The phase-pure rocksalt structure (Fm3¯m) was confirmed by Rietveld analysis of the XRD pattern. The relative density of the sample flash sintered at 100 Vcm-1 and 900 mA was close to ∼95%. Uniform spatial distribution of all the elements was confirmed by elemental mapping. © 2020 Elsevier Ltd