Monte Carlo study of ordering and domain growth in a class of fcc-alloy models

Ordering processes in fcc-alloys with composition A3B (like Cu3Au,Cu3Pd,CoPt3, etc.) are investigated by Monte Carlo simulation within a class of lattice models based on nearest-neighbor (NN) and second-neighbor (NNN) interactions. Using an atom–vacancy exchange algorithm, we study the growth of ordered domains following a temperature quench below the ordering spinodal. For zero NNN-interactions we observe an anomalously slow growth of the domain size L(t)∼tα, where α∼1/4 within our accessible timescales. With increasing NNN-interactions domain growth becomes faster and α gradually approaches the value 12 as predicted by the conventional Lifshitz–Allen–Cahn theory.