  The production of nanopatterns on the surfaces of targets irradiated by ion
beams at low and intermediate energies has developed during the present decade
to a salient degree of control over the main pattern features. However, there
is still a wide experimental scatter in the type and relevance of various
dynamic interfacial properties induced by this technique as a function of
system type and parameters. In parallel, diverse theoretical models exist that
differ in their capabilities to reproduce such a wide range of experimental
features. We provide an overview of the most recent studies of nanoripple and
dot production by ion-beam sputtering, with special attention to the comparison
between experiments and (continuum) models, and with a focus on those issues
that remain open or, at least, ambiguous. These are perhaps more evident for
the case of nanodot patterns on amorphizable targets than for the case of
nanoripples due, possibly, to the relative novelty of the former. The pattern
properties to be considered are those of potential increased technological
importance, such as the variation of nanodot size with parameters like ion
energy, target temperature and sputtering time (i.e., fluence), as well as the
conditions under which the quality of the pattern order is enhanced, issues
such as wavelength coarsening and order enhancement becoming relevant.
