Superheating of nanocrystals embedded in matrix

In terms of a model for size-dependent melting and the Lindemann criterion, a model to interpret superheating of nanocrystals embedded in a matrix has been developed. When a ratio, alpha, between the mean square displacement of the surface atoms and that of interior ones for the nanocrystals, is sma ller than 1, superheating arises when the nanocrystals have coherent or sem i-coherent interfaces with the matrix which has a higher melting temperatur e than the nanocrystals. Moreover, the atomic diameter of the matrix should be smaller than that of the nanocrystals. The model prediction shows good agreement with the experimental evidence. (C) 2000 Elsevier Science B.V. Al l rights reserved.