VAPORIZATION OF SOLID SILVER .2. MACROSCOPIC SURFACE ROUGHENING

Certain morphological features developed during the vaporization of solid silver have been found to correlate with crystallography and environment. Through the results obtained in related kinetic measurements, capillarity forces are shown to be responsible for the hill and valley roughness that is developed. On the basis of the deduced origin, a model for the roughening process is developed. An orientation dependence of the surface morphology, vaporization faceting, is shown to demonstrate the presence of cusped minima in the surface-energy-orientation relationship for silver at the {111} and {100} orientations. Evidence for the adsorption of O2, acetone, CH 3, H2S, and Cl2 on Ag during vaporization was obtained. The results indicate that a C impurity is deposited on the surface by the interaction between carbon-bearing gases and the vaporizing silver and that the C impurity adsorbs preferentially at surface defects and tends to blunt the surface-energy cusps at the low-index orientations. Absorbed oxygen was found to react with other impurities to form desorbable surface species. © 1969 The American Institute of Physics.