Basal-plane stacking-fault energies of Mg: A first-principles study of Li- and Al-alloying effects

Alloying effects due to Li and Al were examined in terms of generalized stacking-fault energies (GSFEs) associated with basal planes of hexagonal close-packed Mg. The GSFE profiles were obtained using a first-principles technique in combination with climbing-image nudged elastic band methods. Our results show that Li alloying can facilitate dislocation-mediated processes while sequential faulting across basal planes becomes favorable with Al alloying. Such a difference is attributed to the fact that the two alloying elements tend to form different types of bond critical points in Mg.