The measurement of local rotations in the electron microscope

Abstract

Electron microscope studies of dislocation arrangements around SiO₂ particles in strained single crystals of copper indicate that there are lattice rotations associated with the structure. These rotations can be seen when the crystal matrix is close to the exact Bragg position. Using a microscope incorporating a Le Poole lens, diffraction patterns can be accurately obtained from an area 3000 Å in diameter. Measurements of Kikuchi line positions on these patterns enable the magnitude and direction of these local lattice rotations to be determined.