Methylsilane on Cu(1 1 1), a STM study of the (3×3)R30°-Cu2Si surface silicide

Scanning tunnelling microscopy has been used to investigate the surface structure of the (3×3)R30°-Cu2Si surface silicide formed on Cu(1 1 1) after adsorption of methylsilane at 595 K. The STM images have shown the presence of a domain wall network on the surface, in the form of a 0.1 Å variation in height on the lateral scale of a minimum of 26 Å. The interpretation of the STM images has indicated that the areas between the domains walls are associated with silicon and copper atoms both residing in either fcc or hcp three-fold hollow sites, whilst the domain wall is a result of an abrupt change enhanced with some electronic contribution.