NANOMETER-RESOLUTION SURFACE-ANALYSIS WITH AUGER ELECTRONS

High spatial resolution Auger electron spectra and images have been ob tained in a UHV scanning transmission electron microscope. An edge res olution of similar to 1 nm has been achieved in Auger electron images of thin specimens. The attenuation lengths of the collected Auger elec trons and the escape depth of the high energy background secondary ele ctrons have been estimated from these nanometer-resolution images. Sur face steps are clearly visible in Auger electron images with high cont rast and high resolution. These techniques have been applied to study a model catalyst system. A method has been developed to estimate the n umber of atoms in metal particles which are smaller than the probe siz e. The most recent results show that Ag clusters containing less than 10 atoms can be readily detected when supported on thin substrates.