Progress in scanning probe microscopy: High resolution force microscopy and spectroscopy

During the last few years the Atomic Force Microscope (AFM) has become capa ble of routinely obtaining atomic resolution when operated with a vibrating cantilever (ac-mode). Local measurement of the tip-sample force (force spe ctroscopy) is a powerful tool for investigations of contact phenomena at th e atomic scale that are important in fields like friction, tribology, atom manipulation and chemical bond formation. This paper reviews several aspect s of the AFM technique such as tip-surface forces, force sensors, operation modes and contrast effects. A study of the Si(111)7 x 7 reconstruction is presented as an example of high resolution AFM imaging.