First-principles study of point defects in Ni₃Al

First-principles modeling of superlattice intrinsic stacking fault energies in Ni3Al based alloys

“…Ni-antisites and vacancies are not accounted for in this study. The added ternary elements have experimentally [35,39,40] and theoretically [41][42][43] proven to show strong site preference to either one of the sublattices or equally to both. Additionally, this preference for some elements, namely, Mn, Fe, Co, Cu, Ag and Au, changes depending on the Ni 3 Al phase composition [42].…”

A first-principles study on the site occupancy behavior of transition metals in L12-Al3Li phase

“…Al is already sufficient in completely describing the T=0 K site preference behavior of any ternary element in L1 2 Al 3 Li. Here the parameter  E X Al Li can be seen as the transfer energy [44,45] and it characterizes the energy required to transfer an X atom from the Al sublattice to the Li sublattice while the Li atom goes to the Al sublattice where the X atom occupied, the reaction can be written via: X Al +Li Li ⟶ X Li +Li Al , and its absolute value is independent of the choice of reference states for the pure elements. In this study, we obtained  E X Ni Al by using equations (2) and 3.…”

On the tetragonality of martensites in ferrous shape memory alloy Fe3Pt: A first-principles study

“…), is also taken into account. Note that there may exist other types of composition conserving defect complexes, eg., the Schottky defect (3Va Fe þ Va Pt ), penta defect (D 5 ¼ 4Va Fe þ Fe Pt ) or hepta-defect (D 7 ¼ 4Va Pt þ 3 Pt Fe ), which, however, are not considered in the present work [38]. With one Fe Pt (Pt Fe ) in the 2 Â 2 Â 2 and 3 Â 3 Â 3 supercells, the corresponding Pt concentrations are 21.875 at.% and 24.074 at.% (28.125 at.% and 25.926 at.%), respectively.…”