Low‐temperature molten salt synthesis of high‐entropy carbide nanopowders.

Synthesis of the powders is critical for achieving the extensive applications of high‐entropy carbides (HECs). Previously reported studies focus mainly on the high‐temperature (>2000 K) synthesis of HEC micro/submicropowder, while the low‐temperature synthesis of HEC nanopowders is rarely studied. Herein we reported the low‐temperature synthesis of HEC nanopowders, namely (Ta0.25Nb0.25Ti0.25V0.25)C (HEC‐1), via molten salt synthesis for the first time. The synthesis possibility of HEC‐1 nanopowders was first theoretically demonstrated by analyzing lattice size difference and chemical reaction thermodynamics based on the first‐principle calculations, and then the angular HEC‐1 nanopowders were successfully synthesized via molten salt synthesis at 1573 K. The as‐synthesized nanopowders possessed the single‐crystal rock‐salt structure of metal carbides and high compositional uniformity from nanoscale to microscale. In addition, their formation mechanism was well interpreted by a classical molten salt‐assisted growth. [ABSTRACT FROM AUTHOR]