Fracture of nanoscale contacts formed between spherical probes and flat samples is studied using an atomic force microscope (AFM) in ultra high vacuum environment. Analysis of the nonlinear elastic behavior observed during the fracture process in the force spectroscopy measurements signifies material extensions both for gold and silica contacts. Separation process begins with an elastic deformation followed by plastic flow of material with atomic scale rearrangements close to the break-off point. Analysis based on classical molecular dynamics show similarity between gold and silicon exhibit entirely different fracture behavior at macroscopic scale. This direct experimental evidence using AFM force measurements convince that fracture of all materials at nanoscale occurs through a ductile process by means of atomic scale rearrangements.
Citation: Applied Physics Letters
Pub Type: Journals
atomic force microscopy, contact mechanics, nanoscale fracture