Atomic Force Microscopy is a powerful instrumental technique to acquire local information on surface properties of materials. The group “Physique des Verres” uses and develops thoroughly the instrument to characterise with metrological care the physico-chemistry of glass surfaces.
Involved researchers : M. Ciccotti, M. George, F. Lechenault, G. Pallarès (Collaboration E. Bauchaud, C. Rountree, D. Bonamy – CEA Saclay) Morphology of polished glass surfaces or of fracture surfaces can be studied by AFM to understand the physics and chemistry of the mechanisms of damaging (by polishing or by crack propagation). The morphologies of these surfaces can contain relevant information either on the polishing process and the surface and sub-surface damage it can induce or on the dynamics (...)
Involved researchers : M. Ciccotti, M. George, A. Grimaldi, G. Pallarès (Collaboration S. Roux – ENS Cachan) In order to investigate in situ propagation of a crack by local scanning probe techniques, the knowledge of surface strain-stress field is vital especially around the corner point singularity that is the intersection between the crack front and the free surface. The mechanisms acting at a crack tip in glass are indeed strongly dependent on the stress gradient developing around the crack front. (...)
Involved researchers : M. Ciccotti, M. George, M. Flemming, A. Grimaldi, G. Pallarès (Collaboration E. Charlaix – LPMCN, UCB Lyon 1) Phase imaging and innovative higher order harmonics investigations are being used to provide a map of the local energy dissipation caused by the tip-sample interaction during the cantilever oscillation. For very stiff substrates such as glass or silicon, the bulk dissipation will be negligible and phase imaging will mostly be sensitive to adhesion and in particular to (...)
Involved researchers : M. Ciccotti (collaboration : L. Vanel, LPMCN, UCLB, Lyon – P-P. Cortet, FAST, Paris XI, Orsay) Using a high speed camera, we study the peeling dynamics of an adhesive tape under a constant load with a special focus on the so-called stick–slip regime of the peeling. It is the first time that the very fast motion of the peeling point has been imaged. The speed of the camera, up to 16 000 fps, allows us to observe and quantify the details of the peeling point motion during the (...)