Template-assisted assembly of transition metal nanoparticles on oxide ultrathin films

In this work we analyse three paradigmatic examples of directed self-assembling and self-organisation of transition metal nanoparticles (NPs) on oxide ultrathin layers grown on single crystal metal surfaces. The major driving forces considered in the description of the NPs assembling process on these nanotemplate systems are the presence in the oxide layer of trapping centres in the form of defects and the metal/oxide interaction. We first summarise the structure of the different oxide nanotemplates, and then we discuss the role of geometric and electronic factors in the formation of ordered NP arrays on the selected systems. It turns out that a defective nanostructured oxide template can drive the organisation of the NPs if the metal NPs are efficiently trapped by the defects and these are accessible via the diffusion of metal adatoms on the surface, which is in turn strongly dependent on the metal/oxide interaction.