Filtered Electron Diffraction Measurements from Thick Polycrystalline Metal Foils

Abstract

DURING the past decade there have been considerable developments in high voltage electron microscopes and diffraction cameras which work reliably at voltages above 300 kV. These instruments are designed for studies of “thick” specimens—foils which it is practicable to prepare by cutting or thinning bulk materials. Metal specimens thinned from bulk are usually several thousand angstroms thick and, if examined at 100 kV, electrons which have been inelastically scattered fog the image or diffraction pattern. By working at much higher voltages the “contrast” of thick specimens is enhanced.