Correlation between stress and band shift on late transition metal (111) surfaces

Abstract

We use ab initio local stress calculations to investigate layer-by-layer ab initio stress inside late transition metal (111) surfaces, focusing on the origin of stress on the surface top layer. It is found that the band shift on each surface layer is strongly correlated with the in-plane stress. For the top layer, this correlation can be explained by the Friedel model. The reduction of the local d-band width due to the coordination reduction is the main origin of both the d-band center shift and in-plane tensile stress. The changes in the directional d-d bonding character analyzed by the in-plane and out-of-plane projected densities of states should be an additional origin of the excess tensile stress, except for Ag explained mainly by the Friedel model.