The steps at the inner surfaces of micro-pipes and nanopipes which contained screw super-dislocations were investigated theoretically. The stress fields of dislocated pipes with small axially symmetrical steps were derived in an approximate closed form. The pipes in an infinite medium, as well as pipes perpendicular to a flat free surface, were examined. The forces which acted on pipe steps were also calculated, and the equilibrium positions for the steps were found. It was shown that sub-surface pipe steps were repulsed from the free surface if they decreased the pipe radius. It was also demonstrated that same-sign steps attracted one another, if they were small, so that the formation of sufficiently large steps at the pipe surface was possible.

Dislocated Micro- and Nanopipes with Surface Steps. M.Y.Gutkin, A.G.Sheinerman: Physica Status Solidi B, 2004, 241[4], 797-817