Atomic Force Microscope Nanoindentation/Scratching

Nanoindentation/Scratching Elastic & plastic material properties are obtained from load-displacement data, but knowledge of the true area of contact is critical. sink-in Load (µN) Stiffness, S: (nm) pile-up

Indentation is Possible With F/D Curves Tip moving in Tip moving out C D A B F E A B C D E F

AFM Nanoindenting Problems With AFM: a) The probe geometry (area) is not know, not quantitative b) The probe motion is not horizontal at contact.

AFM Scratching When Scratching With the AFM, there is a torsion on the cantilever so the probe area changes.

AFM Image of nanoindents in a surface. Nanoindentation Characterization The AFM is ideal for characterizing nanoindents and nano scratches in a surface. AFM Image of nanoindents in a surface.

Summary All AFM instruments can create nanoindents and nanoscratches in a surface. The technique is not quantitative because the probe/surface angle is not characterized The AFM is useful for characterizing nanoindents and nanoscratches.