Adhesive energy and charge transfer for MgO/Cu heterophase interfaces

Local-density-functional-theory (LDFT) calculations within the plane-wave pseudopotential framework are performed for two polar (111) and two nonpolar (100) MgO/Cu interfaces. The polar interfaces have larger works of adhesion than nonpolar ones, consistent with field-ion and electron-microscopy observations of (111) interfaces in internally oxidized specimens. Large shifts in the potential of the interface layer relative to the bulk occur in the polar but not in the nonpolar interfaces. For both polar and nonpolar interfaces, the charge transfer profile is essentially confined to two layers on each side of the interface. © 1996 The American Physical Society.