Ion beam techniques for specimen preparation

Ion erosion has proved to be very effective technique for preparing thin specimens for transmission electron microscopy. It can be applied to metals, insulators, composites and brittle or porous materials. Specimens are thinned to transparency with saddle-field ion sources which produce intense beams of 1.5 mm diameter. In scanning electron microscopy and optical microscopy, ion cleaning can reveal surface features obscured as a result of mechanical treatment or chemical contamination. Surfaces up to 1 cm diameter can be cleaned with a wide beam source, while largely avoiding the introduction of artifacts by randomizing the angle of incidence of the beam on the specimen. (author)