Abstract
The effect on the Volta potential, measured from second phase particles in beryllium, by the thin layer of hydrocarbon contamination pyrolised onto the surface under the action of an electron beam during secondary electron imaging has been investigated. Despite being only a few nanometres thick, this contamination has a significant influence on the Volta potential of second phase particles of interest. This work shows that such contamination can have a substantial effect on the measured potential of particles, acting to increase or decrease the Volta potential difference compared to the metallic matrix