NUCLEATED AND CONTINUOUS ORDERING IN CU3AU - COMMENT

In a recent Letter by Ludwig et al.$ sup 1 the early-stage ordering kinetics in Cu3Au were studied. For samples quenched from a disordered state to temperatures just below the order-disorder transition, it was shown that within the resolution of the experiment, the short-range-order diffuse intensity near the (100) superlattice point initially relaxed in a manner consistent with the predictions of (linear) spinodal ordering theory;2 the corresponding spinodal temperature (Tsp) was found to be T=Ttr-Tsp=34 K below the order-disorder transition temperature (Ttr) of 663 K, in good agreement with the value measured by Chen, Cohen, and Ghosh3 of T=24.2 K. © 1991 The American Physical Society.