Electron and phonon mechanisms of friction in crystalline solids in atomically close contact at low temperatures

Recent experimental and theoretical studies have shown that an atomically c lose contact between two crystalline solids can be free from friction of re st in the event that their lattice constants are incommensurate and the int eraction at their interface does not exceed a certain threshold value. In t his case, the sole mechanisms of friction are the phonon emission and the e xcitation of conduction electrons. Theoretical estimations of both phonon a nd electron contributions to the frictional force have been carried out (th e latter contribution has been considered both in the normal and supercondu cting states of metal). (C) 2000 MAIK "Nauka/Interperiodica".