Phase transformations and structure of Ni–Mn–In alloys with varying ratio Ni/Mn

The fine structure of Ni–Mn–In alloys has been studied when manganese atoms are substituted for nickel atoms in an annealing state. The concentration dependence of the critical temperatures and the structures of the alloys have been discussed. It has been found that, as manganese atoms replace nickel atoms, the structure after annealing is changed from a two-phase ($L2_1$ + martensite) to single-phase $L2_1$ structure. The martensitic transformation in Ni$_{47}$Mn$_{42}$In$_{11}$ alloy is accompanied by the formation of modulated 14$M$ martensite.