The interface structure and the kinetics of a spinhyphen;1 antiferromagnetic Ising model are investigated and applied to crystal growth. For a certain range of model parameters the system undergoes two phase transitions: crystallization (nonmagnetic to magnetic) and an orderndash;disorder (antiferromagnetic) transition of the sublattice ordering in thesolidphase. Thus there are two interfaces associated with the three different phases. The structure of each interface is described by a tanh profile in a timehyphen;dependent Ginzburgndash;Landau approach. Various properties of the interfaces which depend on the driving force are studied. A remarkable change in structure is observed for large interface velocities: If the interface between anorderedhyphen;solidphase and agasphase exceeds a critical velocity, adisorderedhyphen;solidphase forms in between, with a width which increases proportional to time (kinetic phase transition).
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