Synthesis, and structure of T2-Al2MgC2

Abstract

The T₁ and T₂ crystalline varieties of the ternary carbide Al₂MgC₂ were synthesized by reacting graphite particles with Mg-Al melts at 930–1020 K. Below 1000 K, the T₁ variety was predominant but little amounts of T₂ were also present. At 1000 K and above, only the T₂ variety was obtained. Assuming a hexagonal close packing of the metal atoms, the crystal structure of T₂-Al₂MgC₂ was determined by Rietveld refinemenent from X-ray powder diffraction data.