Combined electron and ion projection microscopy

Abstract

We have designed a bright, atomic-size gas ion source for imaging partly transparent samples in a geometric projection mode. Combined with electron holography, this ion projection microscope supplements the holograms by generating a shadow image with ions. Helium ions are used to sputter carbon fibers down to only a few nanometers in diameter, which were subsequently imaged with electrons. Hydrogen ions are used to deposit charges on carbon fiber networks, which can then be imaged and neutralized with a high electron flux. Finally, we present preliminary data of magnetic structures, taking advantage of the different deflections due to the Lorentz force of ions and electrons, and obtain complementary image information on small magnetic particles. © 1993.