Structural variations in the ternary system HfAl2−xCux (x = 0.2-1.0)

► Ternary compounds HfAl2−xCux (x = 0.49, 0.88, 1.04) are characterized. ► The structure type altered in a sequence MgCu2 → MgNi2 → MgZn2. ► These phases were stabilized by interatomic Cu-Al interactions.