Point defect concentrations of L1 ₂ ‐Al ₃ X(Sc, Zr, Er)

Abstract

Abstract The point defect concentrations of L1 2 ‐Al 3 X(Sc, Zr, Er) were systematically investigated using the first‐principle calculations with thermodynamics approach. The results show that the constitutional point defects of off‐stoichiometric L1 2 ‐Al 3 X(Sc, Zr, Er) prefer to occur in X sublattice, that is X anti‐site in X‐rich alloy and X vacancy in Al‐rich alloy, respectively. And Al anti‐site also has a high density in Al‐rich L1 2 ‐Al 3 X(Sc, Er). It is found that the point defect concentrations of stoichiometric L1 2 ‐Al 3 X(Sc, Zr) follow in the sequence as: Al vacancies (V Al ) > X vacancies (V X ) > X anti‐sites (X Al ) > Al anti‐sites (Al X ). The point defect concentration of stoichiometric Al 3 Er is similar to that of L1 2 ‐Al 3 X(Sc, Zr). The result suggests that the Al vacancy (V Al ) is a dominant point defect in L1 2 ‐Al 3 X(Sc, Zr, Er). A simple parameter – can be used for a rough estimation of the point defect concentrations in L1 2 ‐Al 3 X structure. Some rules of point defect concentrations for L1 2 ‐Al 3 X(Sc, Zr, Er) are also revealed.