Magnetic properties of heusler alloys Ni3−xMnxSn

Heusler alloys with composition corresponding to x = 1, 1.2, 1.3, 1.5, 1.65, 1.8 and 1.9 have been prepared. The saturation magnetization and the paramagnetic moment show a maximum at x = 1.3. The manganese atoms are distributed over octahedral and tetrahedral sites with different magnetic moments (μ_ferro(oct.) = 4μ_B, μ_ferro(tetr.) = 0μ_B). Furthermore there is a certain degree of Mn/Sn disorder with Mn atoms on Sn-sites coupled antiferromagnetically to the Mn sublattice. Using a x_g versus 1/H plot, considerable temperature independent paramagnetism is found far below the Curie-temperature (80 K).