Résumé
Nanotribology with an atomic force microscope (AFM) requires an accurate calibration of the mechanical response of the cantilever. To determine the friction coefficient on the nanoscale, we have developed a new calibration method to determine the normal and lateral cantilever stiffness, kNcantilever and kLcantilever, used to calculate the normal and friction forces, which allow us to calculate the nanofriction coefficient μ. Comparative experiments on a silicon wafer with two cantilevers of different dimensions validate our calibration method. The nanofriction coefficient μ of two materials, one silicate glass and the same glass with a 100 Å SnO2 layer, has been measured by AFM after calibrating the cantilever stiffness. The different values of μ show the lubrication effects of the SnO2 layer on the nanoscale.