Antiferromagnetic spin-1 Ising model. II. Interface structure and kinetic phase transition

Abstract

The interface structure and the kinetics of a spin-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 order–disorder (antiferromagnetic) transition of the sublattice ordering in the solid phase. Thus there are two interfaces associated with the three different phases. The structure of each interface is described by a tanh profile in a time-dependent Ginzburg–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 an ordered-solid phase and a gas phase exceeds a critical velocity, a disordered-solid phase forms in between, with a width which increases proportional to time (kinetic phase transition).