title: Collective concerted motion in a molecular adlayer visualized through the surface diffusion of isolated vacancies.
abstract: We have measured STM movies to study the diffusion of individual vacancies in a self-assembled layer of a tetrathiafulvalene derivative (exTTF) on Au(111) at room temperature. The diffusion is anisotropic, being faster along the compact direction of the molecular lattice. A detailed analysis of the anisotropic displacement distribution of the single vacancies shows that the relative abundance of double jumps (that is, the collective motion of molecular dimers) with respect to single jumps is rather large, the number of double jumps being more than 20% of the diffusion events. We conjecture that the relative abundances of long jumps might be related to the strength of the intermolecular bonding and the misfit of the molecular overlayer with the substrate lattice.
authors: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Christian
authors: C
authors: Urban
authors: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Roberto
authors: R
authors: Otero
authors: Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, 28049 Madrid, Spain.
authors: David
authors: D
authors: Écija
authors: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Marta
authors: M
authors: Trelka
authors: Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, 28049 Madrid, Spain.
authors: Nazario
authors: N
authors: Martín
authors: Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.
authors: José M
authors: JM
authors: Gallego
authors: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Rodolfo
authors: R
authors: Miranda
mesh_terms: D004058:Diffusion; D019281:Dimerization; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008562:Membrane Glycoproteins; D008958:Models, Molecular; D009038:Motion; D013499:Surface Properties
chemical_list: D006571:Heterocyclic Compounds; D008562:Membrane Glycoproteins; C048022:substrate adhesion molecules; C063887:tetrathiafulvalene