Anti-Phase Domains in Gold-Copper-Zinc Ordered Alloys Revealed by Electron Microscope

Using thin evaporated films of gold-copper-zinc ternary ordered alloys, the line-up of anti-phase domains has been observed as parallel lines on transmission electron micrographs of bright field, down to a domain size of about 8Å. The lattice modulation accompanying anti-phase domains, i.e. the periodic error of lattice spacing or scattering factor with the same period as a domain size, has again been verified to play an important role in forming the satellites around the direct spot on a diffraction pattern, and hence, in forming the parallel lines on electron-microscopic images. Two-thirds of the intensity of the satellites have been estimated in the present alloy films to arise from the modulation, and the rest probably from double diffraction.