Experimental study of smoothing kinetics on a rough surface

The smoothing kinetics of a rough surface have been studied using time-resolved high resolution low energy electron diffraction. By depositing ∼100 monolayers of Cu on Cu(100) near room temperature, a rough surface results with an initial morphology of multilevel, roughly circular terraces separated by monatomic steps. Upon annealing at elevated temperatures, two growth regimes are distinguished for the average terrace width L(t) versus time t: The earlier one varies as ${\mathit{t}}^{1/3}$, consistent with kinetics driven by the line tension of curved step edges, and the later one follows ${\mathit{t}}^{1/5}$. Also, in the ${\mathit{t}}^{1/3}$ growth regime, scaling is observed.