Abstract
The melting and freezing processes of silicon were investigated by in-situ high resolution transmission electron microscopy (HRTEM) and image processing. Atomic structures of (111) interface planes of the solid and liquid phases have been examined. It is revealed that the interface goes back and forth by the lateral motion of atomic steps on (111) planes as the temperature is changed. A transition region of about 1nm thickness is found to exist between the solid and liquid phases.