Fluctuational electromagnetic interaction of the tip of a scanning microscope with the surface of a solid

A general formula for the lateral frictional force acting on the tip of a scanning microscope moving parallel to a surface with a velocity V is obtained within fluctuational electromagnetic theory. The contributions of various polarization mechanisms to this force are analyzed. The dependences of the lateral forces on the velocity, radius of curvature, and distance of the tip from the surface, as well as the temperature and the dielectric properties of the tribological contact are obtained. It is shown for the first time that the lateral forces can change sign and become accelerating for a definite combination of dielectric functions of the tip and the surface. Pis’ma Zh. Tekh. Fiz. 25, 10–16 (June 26, 1999)