The medium-range orders transition in liquid Fe–Al alloys

Abstract We observed the transition of medium-range orders (MROs) and physical properties in liquid Fe–Al alloys by using ab initio molecular dynamics simulation. Above 66 at. % Al, only Fe–Fe MRO exists, while in other binary Fe–Al alloys studied Fe–Fe and Al–Al MROs coexist, and below 50 at. % Al, Al–Al MRO turns to be dominant. The curve of short-range order around Fe atoms versus Al content also shows a juncture at 66 at. % Al above which polyhedron type increase significantly, correspondingly a significant decrease of the average magnetic moment per Fe atom is observed. In addition, the self-diffusion coefficient of Al atom increases sharply above 66 at. % Al.