Two-dimensional metal-organic networks as templates for the self-assembly of atom and cluster arrays

This thesis presents a study of the use of two-dimensional metal-organic systems as templates for the organization of metal atoms and clusters on surfaces. We start with a systematic characterization of the metal-organic porous networks formed on Cu(111) by polyphenyl-dicarbonitrile molecules, and of the temperature dependence of the assembly process, leading to a variety of geometrical structures. Using molecules of two different lengths we observe networks with distinct periodicities, and we reveal a competition between the different interactions governing the assembly. We also study the self-assembly of a singlemoleculemagnet on supported graphene, observing the same disposition as in a layer of the molecular crystal, which explains the high magnetic anisotropy measured for the system. The metal-organic template is used to organize metal atoms and clusters in the network pores, obtaining a regular array of clusters with a narrow size distribution. We demonstrate how this approach can be used to produce clusters of different elements, such as Fe, Co and Er, as well as mixed transition metal rare earth metal clusters. Otherwise, the metal-organic networks can be used to organize Fe atoms under the molecules, in which case a two-orbital Kondo systemwith amarked spatial dependence is obtained. After characterizing the magnetic properties of Fe atoms adsorbed on bare Cu(111), we use a combination of scanning tunneling spectroscopy, density functional theory and x-ray absorption and dichroism to study the Kondo effect of the Fe-molecule system, identifying the involved magnetic orbitals and demonstrating that they are both Kondo screened.