Photo of Single Atoms by Electron Microscope Available to Purchase

A University of Chicago group using a high‐resolution (5‐Å) scanning electron microscope believes it has obtained pictures of single atoms of uranium and thorium deposited on a thin carbon substrate. Albert Crewe, Joseph Wall and John Langmore reported (Science 168, 1338, 1970) that by detecting the ratio of elastic to inelastically scattered electrons from the high‐Z atoms, they were able to visualize individual atoms. The pictures, displayed on an oscilloscope, show bright spots in the kinds of locations expected by the experimenters. Because of the limitation of the 5‐Å resolving power, the Chicago group constructed various molecules containing heavy atoms spaced further apart than 5 Å.