Experimental study of ordering kinetics in a highly degenerate superlattice

The evolution of domain ordering is studied with use of real-time X-ray scattering in stage 2, 4, and 6 SbCl5-intercalated graphite, an experimental realization of a 14-state quasi-two-dimensional superlattice. Quenching from the disordered phase reveals scaling behavior L = about t to the alpha, with alpha = 0.52 + or - 0.05. Evidence for defect pinning is observed, leading to very sluggish long-time kinetics. The experimental findings are discussed in terms of recent theoretical predictions and Monte Carlo simulations of highly degenerate systems.