Kinetics of ordering for a ternary alloy in the pair approximation

The kinetics of ordering in the bcc ternary alloy is investigated by means of the micromaster equation method in the pair approximation. The time evol ution of the long-range order and short-range order parameters are calculat ed. A transient ordered state results in distinct features, such as stepwis e variation, overshooting effects, and peaks in the evolution to different equilibrium phases. It is found that the development of short-range order i n the ordering stage of the transient ordered state is different from that in the equilibrium phase. Short-range order relaxes gradually in the orderi ng stage of the transient ordered state in contrast to the fast change of s hort-range order in the ordering stage of the equilibrium phase. (C) 2000 A merican Institute of Physics. [S0021-9606(00)51246-X].