NUMERICAL STUDY OF A MORPHOLOGY DIAGRAM IN THE LARGE UNDERCOOLING LIMIT USING A PHASE-FIELD MODEL

We present a numerical study of asymptotic late-stage growth in a phas e-field model. After a long transient time the patterns are independen t of initial conditions, and have a well-defined shape-preserving enve lope which propagates at constant velocity. To distinguish between imp licit and explicit anisotropies, a model with explicit fourfold anisot ropy is solved on a triangular lattice. Distinct morphologies are obse rved, characterized by the envelope shape and by their constituent gro wth elements (dendrites, parity-broken dendrites, or tip-splitting fin gers).