Synthesis, structure, magnetic and half-metallic properties of Co(2−x)Ru(x)MnSi (x = 0, 0.25, 0.5, 0.75, 1) compounds

A series of Co(2−x)Ru(x)MnSi (x = 0, 0.25, 0.5, 0.75, 1) Heusler compounds were successfully synthesized. The heat-treatment conditions were crucial to make the materials form a single phase with a Heusler structure. With increasing Ru content, the half-metallic gap, lattice parameters and magnetization are continuously adjustable in a wide range. The Co(2−x)Ru(x)MnSi (x = 0, 0.25) compounds are rigorous half-metals and show a T (3) dependence of resistance at low temperature. The Co(2−x)Ru(x)MnSi (x = 0.5, 0.75, 1) Heusler compounds are the nearly half-metallic materials and show a semiconductive dependence of resistance at low temperature. The experimental magnetization is consistent with that in theory and follows the Slater–Pauling rule. The Curie temperature is higher than 750 K for all Co(2−x)Ru(x)MnSi Heusler compounds.