Ag (1Â 0Â 0)/MgO (1Â 0Â 0) interface: A van der Waals density functional study

In the present work, we have investigated the interface of Ag (1 0 0) thin films epitaxially grown on the MgO (1 0 0) substrate by using three distinct functionals: the conventional GGA and LDA functionals, and the recently developed non-local vdW-DF functional. The vdW-DF functional can successfully repeat both the structural and energetically details of the interface in the experiments. As expected, the GGA significantly underestimates the interfacial cohesion. Although the adhesion energies obtained by the LDA functional are close to those by vdW-DF, LDA cannot describe the long-range interaction of the interface accurately as vdW-DF does when the Ag thin films are away from the MgO substrate. We propose that the vdW correction should be taken into account for studying the physical and chemical properties of the metal-ceramic interfaces bound by the weak interaction.