The Ternary Nitrides GaFe₃N and AlFe₃N: Improved Synthesis and Magnetic Properties

The recently published two-step ammonolysis was adapted to the first synthesis of GaFe 3 N as a pure phase and AlFe 3 N with a very high phase purity. Similar to archetypal γ′-Fe 4 N ( a = 3.7900(6) Å), the ternary nitride GaFe 3 N adopts a perovskite-like structure in space group Pm 3̅ m with a slightly enlarged lattice parameter of a = 3.7974(1) Å. The magnetic characterization clearly evidences that GaFe 3 N is an antiferromagnet. The systematic exchange of Ga by Fe in going from GaFe 3 N to γ′-Fe 4 N results in a change from antiferromagnetic to ferromagnetic behavior. In contrast, the homologous ternary nitride AlFe 3 N shows a statistical Al/Fe substitution which results in space group Fm 3̅ m . AlFe 3 N can be classified as a soft ferromagnetic nitride.