Entropy-stabilized oxides with medium configurational entropy

Abstract

Medium-entropy oxides, ((Mg1/3Co1/3Ni1/3)1-xZnx)O with x between 0.292 and 0.388, were synthesized by sintering the corresponding powder mixtures and proven to be entropy stabilized. The enthalpy of mixing of these oxides was estimated from their critical formation temperatures. The result showed that the enthalpy of mixing was linearly related to the ZnO concentration. The critical temperature for other compositions in the system was estimated using the extrapolated mixing enthalpy. It is found that the predicted Tc is consistent with experimental results.