Kinetic evolution of unmixing in an AlLi alloy using x-ray intensity fluctuation spectroscopy - art. no. 036108

Irreversible decomposition of an AlLi single crystal has been studied by x- ray photon correlation spectroscopy. The precipitate coarsening follows a u niversal behavior, as measured by the time-resolved average scattering. Usi ng coherent scattering, two-time correlation functions have been measured. The time evolution of the speckle pattern gives new insight into the proces s of unmixing; at least two regimes govern this evaporation-condensation co arsening process. One is related to the overall arrangement of precipitates , and the characteristic time is linear with annealing time. The other is r elated to the motion of interfaces and is related to Pored's law.