## Abstract

We simulate coarsening in an alloy at 50% concentration using the Ising model, under either Kawasaki (K-) or vacancy (V-) dynamics, on three different lattices (sc, fcc, bcc) at five different temperatures. At times t greater than 2000 MCS the first zero R of the spherically averaged pair correlation function obeys R˜R_{0}+(?t)^{1/3} where R_{0}, ? are constants. As the temperature falls, ?_{K} (the value of ? for K-dynamics) falls but ?_{V} rises, so that at low temperatures ?_{V}»?_{K}. The ratio ?_{K}/?_{V} is approximately proportional to the equilibrium concentration of minority atoms in either phase. For the various lattices, the values of ? are roughly proportional to the diffusivities and, therefore, to the squared nearest-neighbour distances, i.e., ?_{sc}:?_{bcc}:?_{fcc}˜4:3:2. At T = 0.9T_{c}, R_{0} is between 2 and 3 for both types of dynamics and all three lattices; as the temperature falls, R_{0} remains near 2 for K-dynamics but falls, very roughly in proportion to the temperature, for V-dynamics.

Original language | English |
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Pages (from-to) | 100-109 |

Number of pages | 10 |

Journal | Physica A: Statistical Mechanics and its Applications |

Volume | 279 |

Issue number | 1 |

DOIs | |

Publication status | Published - 1 May 2000 |