Role of Surface Defects in the Epitaxial Growth of Some fcc Metals on Potassium Chloride Cleaved in Ultrahigh Vacuum

Abstract

It has been found that surface defects produced by electron irradiation play a critical role in the formation of single‐crystalline films of typical fcc metals such as Au, Ag, and Cu on UHV‐cleaved KCl. Epitaxial films of the (100)_Au∥(100)_KCl, [100]_Au∥[100]_KCl orientation were produced in a wide range of substrate temperatures on irradiated surfaces at low supersaturation levels. Surface defects produced by irradiation provide nucleation sites which strongly favor the epitaxial orientation for nuclei. The high sensitivity of film orientation to irradiation treatment of the substrate suggests that other known critical factors such vacuum condition and surface composition may also influence epitaxy through their effect on the nature of the substrate surface upon which nucleation occurs.