Abstract
This review addresses the quantum mechanical
nature of the formation and stability of ultrathin
metal lms. The competition between quantum con nement,
charge spilling e ects, and Friedel oscillations determines
whether an atomically smooth metal lm will
be marginally, critically, or magically stable or totally
unstable against roughening. Pb(111) lms represent a
special case, not only because of strong quantum oscillations
in the stability of two-dimensional thin lms
but also because of the exceptionally fast coarsening of
Pb nanoclusters. The latter appears to be due to the
combined e ects of size quantization and the existence
of a unique mass exchange medium in the form of an unusually dense and highly dynamic wetting layer. The
consequences of size quantization on the physical and
chemical properties of the lms are profound, some of
which will be highlighted in this review.