Dynamic lateral force microscopy with true atomic resolution

We present frequency modulation dynamic lateral force microscopy with true atomic resolution. Torsional resonance mode of a commercially available rectangular cantilever was used to detect interaction lateral force gradients caused between the tip and the sample surface. A slight negative frequency shift of the torsional resonance frequency was observed before contact to the silicon surface. Individual adatoms in a unit cell of the Si(111)-7x7 reconstructed surface were imaged with the constant frequency shift mode. Two sets of the neighboring corner adatoms and one set of the center adatoms on the dithering direction of the tip were connected on the image. This method has a great potential to observe friction between single atoms. (C) 2005 American Institute of Physics.