High field magnetization in equilibrium ordered nickel-manganese alloys

The equilibrium ordered states for 400°C and 500°C annealing in Ni-Mn alloys near the Ni
3
Mn composition have been investigated. The results indicate distinctly different order configurations for the two temperatures. At 400°C, homogeneous long range order results, with a saturation magnetization which is relatively insensitive to composition. At 500°C, the data suggest that the ordering is inhomogeneous, with the nucleation and growth of stoichiometric Ni
3
Mn clusters in a Mn-or Ni-rich matrix, depending on composition.