AN ELECTRON DIFFRACTION STUDY OF ELECTROPOLISHED IRON

Abstract

Iron has been electropolished over a range of voltage and current in the acetic acid–perchloric acid bath. Under optimum conditions an "atomically smooth" surface has been obtained as evidenced by marked refraction effects in the electron diffraction patterns. There is also evidence for a thin film on the electropolished surface which thickens on further exposure to air to form a preferentially oriented cubic iron oxide. Light etching in nitric acid removed the film and formed a surface which, on diffraction, gave the more normal spot pattern of iron.