Single-Step Carbothermal Synthesis of High-Purity MAX Phase Powders

The M(n+1)AX(n) phases Cr2GeC and Cr2GaC were synthesized with high phase-purity directly from Cr2O3; Ge or Ga; and C using a single-step carbothermal reduction. X-ray diffraction and scanning electron microscope analysis of the materials shows them to be >99 mol% Cr2GeC and 92 mol% Cr2GaC, respectively. Extension to non-Cr systems is briefly demonstrated by applying the method to the synthesis of V2GeC.