DEPENDENCE OF SUPERCOOLING OF A LIQUID ON ITS OVERHEATING

The degree of overheating of a melt often plays a significant role in determining its supercooling behavior and thus the nucleation and grow th of crystals and their qualities. However, the relationship between the level of melt overheating and the resulting degree of supercooling is far from being understood, It is demonstrated that the dependence of the degree of supercooling on the level of melt overheating for bis muth is a function of the duration of melt overheating above its melti ng point. Depending on the duration, the degree of supercooling can in crease either discontinuously or continuously with the level of melt o verheating. These observations, which can be linked to the transient e volution of short-range structures during melting and solidification, suggest that tile similar observations should also be observable for s ubstances exhibiting substantially different short-range structures in the solid and liquid state. (C) 1997 American Institute of Physics.