The anisotropy of antiphase boundary (APB) energies in ordered L1 2 - Ni3Al is studied, owing to its importance in understanding the anomalous flow behavior of this intermetallic compound. We report first-principle calculations for two types of APBs in the ordered compound: (001) and (111). The magnetic perturbations associated with these APBs are calculated as a function of supercell size to ensure that their periodic images are isolated both magnetically and elastically. The magnetic perturbation associated with the (111) APB is wider than that of the (001) APB. The fully relaxed, spin-polarized APB energies for (001) and (111) APBs are calculated to be 82 mJ/ m2 and 177 mJ/ m2, respectively. The resulting anisotropy ratio of σ(111)/σ(001) =2.16, which is significantly higher than previously reported values, suggests that cross-slip between (001) and (111) is highly favorable.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)