Adsorption and desorption kinetics of NTCDA molecules on Ag(111) and Au(111) surfaces studied by ion scattering. Issue 1 (1st February 2017)

• Record Type: Journal Article
• Authors: Jia, Juanjuan; Esaulov, Vladimir A.; Bendounan, Azzedine
• Is Part Of: Radiation effects and defects in solids. Volume 172:Issue 1/2(2017)
• Page Start: 39
• Page End: 47
• Publication Date: 2017-02-01
• Subjects: Ion scattering -- chemisorption -- NTCDA -- Ag -- Au -- planar molecule; Radiation chemistry -- Periodicals; Crystals -- Defects -- Periodicals; Crystal lattices -- Periodicals; 530.416
• DOI: 10.1080/10420150.2017.1281276
• Languages: English
• ISSNs: 1042-0150

Abstract

ABSTRACT: A study of adsorption of NTCDA (1, 4, 5, 8-naphthalene tetracarboxylic dianhydride) on Ag(111) and Au(111) surfaces is presented. The adsorption kinetics is followed at room temperature from the submonolayer range upto thin film formation using time-of-flight scattering and recoiling spectroscopy in which atomic fragments and incident scattered particles are detected. The desorption kinetics is similarly followed from room temperature to upto a few hundred degrees. On Ag adsorption it first proceeds rapidly and then a slower uptake is observed prior to multilayer formation. This is ascribed to the formation of first a relaxed (as indicated by others) and then compressed monolayer phases. We attribute compressed phase desorption to temperatures below 400 K and desorption of the relaxed phase is ascribed to the 400–450 K region confirming conclusions of Braatz et al. In case of the Au surface the kinetics of adsorption at low deposition flux is very slow and accelerates after some molecules are initially adsorbed. We associate this to the very low binding energy of single molecules as predicted by theory. Subsequent higher sticking probability can be associated with intermolecular Van der Waals forces which contribute strongly to the adsorption energy.