In-situ observation of melting of fine lead particles by high-resolution electron microscopy

The melting behavior of fine lead particles (smaller than 10 nm in diameter ) was studied by high-resolution electron microscopy. The lead particles we re grown by evaporation on an amorphous carbon substrate in the specimen ch amber of electron microscope at 10(-7) Pa, so that their surfaces were kept free from any contamination. The melting process was recorded on videotape . It was found that a diffused layer appears before melting and that the le ad particles fluctuate between solid and liquid phases at temperatures slig htly above the melting temperature. This behavior seems to be due to a coex istence state which is predicted from theoretical investigations. (C) 1999 Elsevier Science B.V. All rights reserved.