Isothermal decomposition of a Au‐60 at.% Pt alloy, quenched from the solid as well as the liquid state, has been studied with the D11 neutron small‐angle scattering spectrometer at ILL, Grenoble. An incident neutron wavelength of 6.7 Å was used and measurements were carried out in the range of scattering vector [β = 4πsin θ/λ] from 2.8 × 10−2 to 21 × 10−2Å−1. The preliminary results indicate that decomposition of this alloy at 550°C takes place by a spinodal mode, although deviations were observed from linear spinodal theory, even at very early times. Slower aging kinetics were observed in liquid‐quenched alloy as compared with solid‐quenched. Liquid quenching is more efficient in suppressing quench clustering than is solid quenching. However, liquid quenching yields an extremely fine‐grained material, which thereby enhances discontinuous precipitation at grain boundaries, competing with decomposition in the bulk. A Rundman–Hilliard analysis was used for the early stages of the spinodal reaction to obtain an interdiffusion coefficient of the order of 10−16 cm2 s−1 at 550°C for the solid‐quenched alloy.
High-energy high-dose Au implantations into Pt have produced an amorphous structure, as observed by transmission electron microscopy. A modulated microstructure has apparently been concurrently formed, and this is concluded to be spinodal decomposition. This result is consistent with independent small-angle neutron-scattering experiments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.