Reflection high-energy electron-diffraction study of melting and solidification of Pb on graphite

Abstract

The melting and solidification of Pb thin films on pyrolytic graphite are investigated in situ by reflection high-energy electron diffraction. Thin films with thicknesses of 4--150 monolayers are investigated. The surface morphology of the thin films were studied by scanning electron microscopy. Superheating of the Pb thin films by $4\ifmmode\pm\else\textpm\fi{}2$ to $12\ifmmode\pm\else\textpm\fi{}2$ K is observed from diffraction intensity measurements. Upon cooling the substrate, the Pb on graphite is seen to supercool by $\ensuremath{\sim}69\ifmmode\pm\else\textpm\fi{}4\mathrm{K}.$