Surface characterisation using atomic force microscopy

The atomic force microscope (AFM) combines several techniques in one instrument for surface characterisation of metals, ceramics, composites, polymers, and thin film coatings, Tapping mode AFM can resolve different phases on heterogeneous surfaces by their adhesion, hardness, and electrical, magnetic, and chemical properties, Simultaneously, quantifiable 3D topographic maps are generated with nanometre in plane resolution and better than 0.1 nm vertical resolution. Areas as large as 120 x 120 mu m can be characterised with some control over specimen temperature. Single profiles up to 10 mm long are possible. Wear and hardness testing of thin film coatings using nanoindentation and nanoscratching can be followed immediately by tapping mode imaging of the tested area. AFM is done in air or liquids, including dilute acids, and can depict, in situ, the minutest morphological changes caused by electrochemical reactions and corrosion, Generally slower than SEM, AFM requires no vacuum or special specimen preparation. Some APM images and data are presented and discussed.