Small-angle X-ray scattering study of the growth kinetics of CuCl nanocrystals in NaCl

The precipitation of CuCl nanocrystals in a NaCl matrix has been studied by time-resolved small-angle X-ray scattering. The experimental results suggest that the nucleation process is accelerated by lattice defects of the matrix remaining in the NaCl lattice after the dissolution of previous nanocrystals at high temperature. The evolution of structural parameters calculated from the scattering curves, such as volume fraction, mean radius and particle number density of the nanocrystals, is discussed in terms of a classical phase separation process but with specific concern for the effect of elastic strains. It was found that Ostwald ripening is effective during the whole period of observation. The effect of elastic strains results in an increase of the critical radius and a decrease of the coarsening rate. The results of the scattering experiments confirm the miscibility gap data determined by exciton spectroscopy.