The stacking fault energy (SFE) in binary and ternary alloys of Al with common alloying elements was studied using density functional theory. Among these alloying elements, Fe further increases the SFE and Ge reduces the SFE of Al. The alloying elements increase the SFE by increasing the directional inhomogeneity in the electronic charge distribution of Al. The maximum value of charge difference on the fault plane, $\mathrm{Max}\left(\mathrm{\Delta }\rho \right)$, is used to characterize how many electrons have been redistributed due to the stacking fault formation, and the SFE increases with $\mathrm{Max}\left(\mathrm{\Delta }\rho \right)$.

• Received 11 December 2006

DOI:https://doi.org/10.1103/PhysRevB.75.224105