The structure of very thin lead films

A scanning electron diffraction system has been used to obtain accurate profiles of electron diffraction intensities from thin films of lead up to 15 in thickness. The facilities of sequential recording of film growth and rejection of loss electrons from measurements enable the intensity profiles to be free from any substrate contribution and also from errors due to inelastically scattered electrons. Fourier transforming this data has yielded structural information which shows that the initial film nuclei do not have an fcc packing sequence. A model is proposed for the structure of nuclei in the early stages of the growth of the film.