The anisotropy of antiphase boundary energies in ordered L12-Ni3Al was studied, owing to its importance in understanding the anomalous flow behavior of this intermetallic compound. First-principles calculations were reported for two types of antiphase boundaries in the ordered compound: (001) and (111). The magnetic perturbations associated with these antiphase boundaries were calculated as a function of super-cell size in order to ensure that their periodic images were isolated both magnetically and elastically. The magnetic perturbation associated with the (111) antiphase boundary was wider than that of the (001) antiphase boundary. The fully relaxed spin-polarized antiphase boundary energies for (001) and (111) antiphase boundaries were calculated to be 82 and 177mJ/m2, respectively. The resulting anisotropy ratio of σ(111)/σ(001) = 2.16, which was significantly higher than previously reported values, suggested that cross-slip between (001) and (111) was highly favorable.

Magnetic Perturbation and Associated Energies of the Antiphase Boundaries in Ordered Ni3Al. Manga, V.R., Saal, J.E., Wang, Y., Crespi, V.H., Liu, Z.K.: Journal of Applied Physics, 2010, 108[10], 103509