The development of oriented crystal growth during condensation of gold, silver and copper films in vacuum, and its systematic dependence on the residual gas pressure and adsorption, and the film thickness, atomic mobility and chemical reactivity

Electron diffraction at grazing incidence shows, as a function of thickness H and air pressure p , the surface structure and growth of Au, Ag and Cu films condensed in vacuum at about 30 Å s −1 at normal incidence on polished stainless steel or glass initially at room temperature. Initial randomly-oriented growth gives place to {111} orientation at H similar 200 Å at low enough p (similar 10 −8 Torr for Au and Ag, <<10 −8 Torr for Cu). As p increases, this H rises to a maximum (similar 750 Å at 5 × 10 −3 Torr for Au, 3300 Å at similar 10 −5 Torr for Ag, and > 1000 Å at < 10 −8 Torr for Cu), then decreases approximately rectilinearly with further increase in log p for p up to about 10 −2 Torr. Loci of similar form at higher H are defined for the later stages: {111} orientation + {111} twinning, then {110} and/or {211} orientation arising by secondary twinning. The results show the general form of the ( H , log p ) loci for onset of the orientations, and the effects of increasing chemical reactivity (oxygen chemisorption), for Au, Ag and Cu. In the higher part of the p range, if the oxygen chemisorption there obeys a Temkin isotherm, then theoretically H is proportional to (log p 0 - log p ), for the onset of the first orientation {111} even if the mobility of the condensed metal atoms is limited to allowing only atoms within a certain distance from the edge of the {111} face to reach the edge and be retained there.