New tools for grazing incidence neutron scattering experiments open perspectives to study nano-scale tribology mechanisms

Using grazing incidence scattering methods allows for depth profiling near surface structures very efficiently Dosch (1986). In parallel, layered structures have been used as resonators to enhance the wave field Kozhevnikov et al. (2007), Khaydukov et al. (2011), Kozhevnikov et al. (2011) and Nesnidal and Walker (1996) that directly increases the scattered intensity too. Third, the combination of these methods with neutron spin echo spectroscopy allows for near surface studies of dynamics Jaksch et al. (2015) and Frielinghaus et al. (2012) that can be correlated to tribological effects on the molecular level. This field of science, the tribology, -so far - has been driven mainly by the surface force balance that measures the macroscopic response of the system (latest research employs also AFM) Raviv et al. (2003) [1], Chung et al. (2016) [2] and Mocny and Klok (2016) [3]. The progress of this method was to reach the nano-scale distances that were necessary to obtain information about the friction of the nano-structures. The proposed method of grazing incidence neutron spin echo spectroscopy gives access to much more detailed information of molecular response to confinement by one or two hard walls, and therefore would pave the way for very rich and precise tribological comparisons of theory with experiments. (C) 2017 The Authors. Published by Elsevier B.V.