Bulk nucleation and amorphous phase formation in highly undercooled molten silicon

Abstract

Solidification of undercooled liquid (l) Si formed by pulsed laser melting of amorphous (a) layers has been studied experimentally and theoretically. Bulk nucleation apparently occurs at a temperature higher than that of the l→a phase transition. Release of latent heat on nucleation is crucial in determining the depth of melting. It is emphasized that bulk nucleation implies that the l→a transition cannot be explained by purely thermodynamic considerations.