CHEMICAL AUTOMATON FOR CRYSTAL-GROWTH - STABLE STRUCTURES FROM NONEQUILIBRIUM PROCESSES

A chemical growth model for binary alloys is presented. At each step, using a simple energetic criterion, an A or B atom is aggregated to th e growing cluster. Two one-dimensional models are considered. The firs t one is a lattice-gas model with short-range decreasing and convex ch emical interactions. It is proved that the growing structures are the so-called uniform structures where the atoms are arranged as regularly as possible and which are known to be the ground state equilibrium st ructures of the same model. When the interactions are not convex, othe r ordered structures can grow for appropriate initial conditions. The second model uses an electronic tight-binding Hamiltonian for which th e growth of uniform structures is also observed.