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 fourteen-state quasi two-dimensional superlattice. Quenching from the disordered phase reveals scaling behavior L~t^α, with α=0.52±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.