A non-linear model for time-dependent occupation of lattice gas sites
is studied. A self-consistent approximation for the diffusion operator
is proposed and studied in discrete and continual forms. It is shown
that self-organization effects in the spinodal region lead to a sponta
neous transformation of an unstable uniform ground state into an array
of self-assembled islands. The relationship between the model and the
theory of first-order phase transitions is discussed. The model is ap
plied to the study of self-organization in three-dimensional adsorbate
s with attractive lateral interactions. A special emphasis is given to
the description of a spontaneous islanding during molecular beam epit
axy and related growth techniques. It is shown that the kinetic parame
ters strongly influence the morphology of space-ordered configurations
of the system. (C) 1998 Elsevier Science B.V. All rights reserved.