Kinetics of Ordering in Cu 3 Au

L1 2 -long-range ordering (LRO) was studied by residual resistometry in Cu 3 Au. Variations of LRO-parameter were produced by isochronal and isothermal heat treatments for different initial states of order. By comparison of order-order and disorder-order relaxations, the contributions to ordering of atomic jumps within ordered domains and of antiphase boundaries were separated. Analysing isothermal annealings yielded ordering energies of vacancies involved.