Medium-entropy (Ti, Zr, Hf)2SC MAX phase

Medium- and high-entropy alloys or ceramics for tuning the physicochemical properties of materials by the combination of multiple principal elements have received much interest. Herein, a medium-entropy (Ti, Zr, Hf)2SC phase was synthesized attributing to the structural and chemical diversity of MAX phases. The crystal structure of (Ti, Zr, Hf)2SC was determined by the Rietveld refinement of XRD, SEM, and atom-resolved TEM along with EDS elemental analysis. Phase evolution of X-ray diffraction patterns and TG/DSC curves were employed to reveal the synthesis mechanism of (Ti, Zr, Hf)2SC from 2TiC–Zr–ZrC-2HfH2-3.2FeS reactant system. The Vicker's hardness and the electrical resistivity of (Ti, Zr, Hf)2SC were found higher than those of Ti2SC, but the thermal conductivity of (Ti, Zr, Hf)2SC was lower.