Silver films condensed at 300 and 90 K: Scanning tunneling microscopy of their surface topography

Scanning tunneling microscopy shows that warm-condensed Ag films consist of a gently rolling surface topography with compact boundary regions. In contrast, cold-condensed films retain structure on the nanometer scale after annealing to room temperature: These intercrystallite channels or trenches show a strong similarity in width (<1-3 nm), separation (5-15 nm), and possibly depth [3-(>4.5) nm] to the surface topographic models for surface-enhanced-Raman- scattering activated films. This suggests that postannealing does not imply the annihilation of channels, also termed "pores" or "cavities," postulated by some current models. © 1985 The American Physical Society.