Transition from Short-Range Order to Long-Range Order in Cu₃Pt by High-Resolution Electron Microscopy

Abstract

We have studied microstructural changes in the transition from short-range order (SRO) to long-range order (LRO) in a Cu-25.1 at%Pt alloy using many-beam imaging techniques with the aid of an image processing method. In the alloy quenched from 923 K, L1₂-type microdomains with the out-of-step relation between neighbors are recognized. With annealing at 793 and 843 K, the microdomains grow to large domains of the L1₂ and L1_2−s type structures, respectively. The results revealed the process of nucleation and growth of ordered domains.