Fe-Phthalocyanine on Cu(111) and Ag(111): A DFT+vdWs investigation

Starting from dyes in the industrial domain, Metal-Phthalocyanine (MPc), a macrocyclic planar organo-metallic molecule, can nowadays be used in various applications at low cost in several areas such as oncology, sensors, catalysts, spintronic devices, to name a few. Some applications require the deposition of these molecules on metallic surfaces, whereas sometimes the bulk molecular system is used. In this work, we study both the bulk system of iron-Phthalocyanine (FePc) and its adsorption on Cu(111) and Ag(111). We investigate the structural, electronic, and magnetic properties of these materials using Density Functional Theory (DFT) taking into consideration van der Waals effects to further reflect the importance of the involved interactions on the properties. We found that the FePc bulk system displays a magnetic state resulting from the metallic central Fe atom. However, the adsorbed FePc partially loses its magnetization when it is deposited on a transition metal surface of Cu(111) or Ag(111). Additionally, both C4 symmetry and C2 symmetry were observed with STM images for FePc/Ag(111) and FePc/Cu(111), respectively. The adsorption is found to be of a strong chemisorption type with relatively large binding energy (-x223C 5 eV/molecule) and charge transfer (-x223C 0.7e(-)) from the metal surface to the molecule.