Contribution of surface state to dislocation dissociation in metallic solids

Abstract

A surface state (Es) is generated in the electronic band structure when a stacking fault (SF) forms due to the violation of the translational symmetry of a crystalline structure at dissociated partial dislocation cores. We found that Es demonstrates a linear relation with the SF energy (SFE), which was evaluated via transmission electron microscopy (TEM) for nonferromagnetic metallic solids, indicating that the SF width is determined by ES on the slip plane for each crystalline structure. Based on this observed relation, for lead, the SFE calculated using density functional theory (48 mJ/m2) is inconsistent with that evaluated via TEM (8 mJ/m2). Furthermore, the relation reveals various peculiarities of aluminum, such as the deep Es resulting from the projected bulk band widely spread beneath the Fermi level and the narrower SF compared with those of other face-centered cubic metallic solids.