Mechanism of the formation of deformation steps of nanometric sizes at the surface of plastically deformed crystals

The mechanism of the formation of nanometric-size deformation steps at the surface of plastically deformed crystals is discussed theoretically. Such steps are detected by means of a scanning tunneling microscope or by high-resolution speed filming. The analysis shows that the exponential step distribution by height is due to the double cross slip (DCS) of screw dislocations and that the growth kinetics of separate steps is deter-mined by the kinetics of the Frank-Read dislocation sources appearing as a result of the DCS.