  The unique three-phase coexistence of metastable B2-FeNi with stable L10-FeNi
and L12-FeNi3 is discovered near edge dislocations in body-centered cubic Fe-Ni
alloys using atomistic simulations. Stable nanoscale precipitate arrays, formed
along the compression side of dislocation lines and defined as linear
complexions, were observed for a wide range of compositions and temperatures.
By analyzing the thermodynamics associated with these phase transitions, we are
able to explain the metastable phase formation and coexistence, in the process
defining new research avenues for theoretical and experimental investigations.
