A phase-field model for the dynamics of a strained solid in contact with it
s melt is developed. The sharp-interface limit of this model reduces to the
continuum equations describing the Asaro-Tiller-Grinfeld instability. In a
ddition, it allows the derivation of generalizations of these equations. Th
e dynamics of extended systems are investigated via the phase-field approac
h which contains an inherent lower length cutoff, thus avoiding cusp singul
arities. General initial conditions lead to coarsening. For periodic states
, this arises via a series of approximate period doublings, the beginning o
f which can be demonstrated analytically. (C) 2001 Elsevier Science B.V, Al
l rights reserved.