Phase equilibria in the Ni-Mn-Sb alloy system

Phase equilibria and ordered phase regions in the Ni-Mn-Sb system at 700 and 900 °C and the martensite phase region at room temperature were determined mainly by the diffusion triple method. It was confirmed that single-phase region of the ordered bcc phases exists in a wide composition range of a central part at both 700 and 900 °C and that the region is divided into two regions of half-Heusler C1_b and full-Heusler L2₁ at 700 °C, while the C1_b phase is missing at 900 °C. The B2 + L2₁ phase separation was also confirmed in a certain composition range near Ni-50%Mn, and the iso-Ms (= RT) line in the L2₁ phase region was also estimated to be located from 12 to 16 at.% Sb.