Effects of monolayer and bilayer silica films on Fe-Phthalocyanine adsorption properties

We explore the adsorption properties of Fe-Phthalocyanine (FePc) molecule at various configurations of silica films supported by Ru(0001) and report on the geometric, electronic and magnetic features of the energetically preferred structures to fully understand the influence of the silica films on the adsorption properties of the FePc molecule. The investigation is carried out with the use of density of functional theory calculations and the self-consistent inclusion of van der Waals interaction. In addition, Oxygen atoms are added to govern the atomic structure of the silica overlayers on the surface. Our results show that both FePc/silica thin film systems exhibit both physisorption and chemisorption simultaneously. In addition, the FePc molecule on each substrate undergoes a symmetry reduction driven by mismatch with the substrates' symmetry as well as the breakup of the degenerate orbitals of Fe.