title: Impact of van der Waals interactions on single asperity friction.
abstract: Single asperity measurements on Si wafers with variable SiO(2) layer thickness, yet identical roughness, revealed the influence of van der Waals (vdW) interactions on friction: on thin (1 nm) SiO(2) layers, higher friction and jump-off forces were observed as compared to thick (150 nm) SiO(2) layers. The vdW interactions were additionally controlled by a set of silanized Si wafers, exhibiting the same trend. The experimental results demonstrate the influence of the subsurface material and are quantitatively described by combining calculations of interactions of the involved materials and the Derjaguin-Müller-Toporov model.
authors.affiliation: Department of Experimental Physics, Saarland University, D-66123 Saarbrücken, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lessel
authors.forename: Peter
authors.initials: P
authors.lastname: Loskill
authors.forename: Florian
authors.initials: F
authors.lastname: Hausen
authors.forename: Nitya Nand
authors.initials: NN
authors.lastname: Gosvami
authors.forename: Roland
authors.initials: R
authors.lastname: Bennewitz
authors.forename: Karin
authors.initials: K
authors.lastname: Jacobs