title: Metal-organic extended 2D structures: Fe-PTCDA on Au(111).
abstract: In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic chains through PTCDA molecules placed perpendicularly, as rungs of a ladder. These structures, stable up to 450 K, can be extended in a 2D layer covering the entire surface and presenting different rotation domains. STM images at both polarities show a contrast reversal between the two molecules at the unit cell. By means of density functional theory (DFT) calculations, we confirm the stability of these structures and that their molecular orbitals are placed separately at the different molecules.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Alvarez
authors.forename: Samuel
authors.initials: S
authors.lastname: Peláez
authors.forename: Renaud
authors.initials: R
authors.lastname: Caillard
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Serena
authors.forename: José A
authors.initials: JA
authors.lastname: Martín-Gago
authors.forename: Javier
authors.initials: J
authors.lastname: Méndez