Investigation of high spin-polarization, magnetic, electronic and half-metallic properties in RuMn2Ge and RuMn2Sb Heusler alloys

Half-metallic ferromagnets RuMn2Ge and RuMn2Sb have been studied in stable F-43m phase. The optimized equilibrium lattice constants in F-43m phase were found to be 5.90 Å and 6.10 Å for RuMn2Ge and RuMn2Sb, respectively. The materials exhibit half-metallic city with an energy gap in the spin-down channel of 0.38 eV for RuMn2Ge and 0.4 eV for RuMn2Sb. The calculated total magnetic moments of 2.0 μB per unit cell for RuMn2Ge and 3.0 μB per unit cell for RuMn2Sb are in good agreement with Slater–Pauling rule. The magnetic moments of Mn-I and Mn-II mainly contribute to the total magnetic moment of the materials and are antiparallel to each other, hence predicting the signature of ferrimagnetism in RuMn2Z alloys. The shifting of bands towards lower energies in spin-down channel for RuMn2Sb may be due to the strong covalent character of bonding than RuMn2Ge.