Rectangular Pits Created on KBr (001) Surface by Electron Stimulated Desorption and Imaged by Au Decoration and C Replication

The surface morphology of KBr (001) irradiated by electrons is observed by first decorating the surface with Au particles and then replicating it with C foils. For the electron irradiation and the subsequent decoration, we integrated an electron-beam gun and a vacuum evaporator. The sample surface was irradiated by a 1.5 keV electron beam; small Au particles were then evaporated onto the surface. Although the decorated sample was prepared in an ultra-high vacuum condition, the C foil was evaporated in a separate high-vacuum evaporator. To avoid deliquescence of the sample surface, contact between the sample and the ambient air was minimized by transporting the sample between the two vacuum chambers in a N2-gas-filled enclosure. Imaging the surface with a transmission electron microscope revealed many rectangular monolayer pits. The mean area of the pits and the associated standard deviation are presented versus temperature; the mean pit area increases with temperature.