Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 109: Tribology and Structure of Surfaces: Misc.

O 109.2: Vortrag

Freitag, 24. März 2017, 11:00–11:15, WIL A317

Temperature dependent Contact Ageing effects for Diamond and Silica Interfaces — •Matthias Vorholzer, Dirk Dietzel, and André Schirmeisen — Institute of Applied Physics, Justus-Liebig-University, Giessen, Germany

Contact ageing describes the temporal evolution of interface conditions. While this topic is well known on the macroscale, recent experiments have shown, that ageing can also play an important role in nanoscale contacts [1,2,3], where ageing is supposed to influence parameters like e.g. interface matching, contact area, or the apparent stiffness of a contact. In most cases nanoscale contact ageing is assumed to be a thermally activated process. Thus, temperature dependent measurements are a viable way to survey and thoroughly explore the relevant interface processes. Here, we present experimental data with well-defined ageing times up to 10 s for Silica-Silica and Silica-Diamond interfaces, gathered with an UHV-AFM between 15 K and 300 K using the slide-hold-slide protocol [1]. Our experimental approach gives access to both static friction and contact stiffness, which can then be compared to theoretical predictions. For each temperature the anticipated logarithmic ageing is observed, yet the temperature dependence contradicts simple scenarios based solely on thermal activation [2]. Thus, more complex and realistic ageing scenarios are currently considered to describe all aspects of contact ageing.

[1] Q. Li et al., Nature 480, 233 (2011)

[2] M. Feldmann et al., PRL 112, 155503 (2014)

[3] M. Feldmann et al., PRL 117, 025502 (2016)