The properties of steps in thermal equilibrium are described in the context
of prediction of the stability and evolution of nanostructures on surfaces
. Experimental techniques for measuring the appropriate step parameters are
described, and simple lattice models for interpreting the observations are
reviewed. The concept of the step chemical potential and its application t
o the prediction of step motion (and therefore surface mass transport) is p
resented in depth. Examples of the application of this step-continuum appro
ach to experimental observations of evolution of surface morphology are pre
sented for morphological phase transitions, the decay of metastable structu
res, and the spontaneous evolution of metastable structure due to kinetic i
nstabilities. (C) 1999 Elsevier Science B.V. All rights reserved.