title: First layer compression and transition to standing second layer of terephthalic acid on Cu(100).
abstract: Terephthalic acid on metal surfaces is a system of high interest for interfacial layers as well as for use in generating surface nanostructures by supramolecular self-assembly. Here we demonstrate structural transitions upon compression of the first layer as well as a significant transition from a flat lying chemisorbed first monolayer to a standing second layer. The second layer structure is stable at 150 °C, but a weakly bound state is observed to desorb molecularly below that temperature, likely a transient mobile state during annealing. Molecular resolution scanning tunnelling microscopy is complemented by X-ray photoelectron spectroscopy and thermal desorption spectroscopy in this study. These results provide general insight in the development of self-assembled organic thin films at surfaces, especially with regard to the nature of the metal/organic interface and growth transitions to maximize first layer packing and obtain a second layer that bridges commensurability with the substrate and a more bulk-like structure.
authors.affiliation: Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, USA. tait@indiana.edu
authors.forename: Steven L
authors.initials: SL
authors.lastname: Tait
authors.forename: Hyuna
authors.initials: H
authors.lastname: Lim
authors.forename: Arjun
authors.initials: A
authors.lastname: Theertham
authors.forename: Peter
authors.initials: P
authors.lastname: Seidel