Fig. 3

Autocorrelations during steady-state deposition. a Growth at 144 °C as a function of Q_||, with fixed Q_z = 0.045 Å⁻¹. Note that the oscillation frequency is independent of Q_||. The  step spacing can be  estimated from 2π/Q_max, where Q_max is the in-plane component of the wave-vector transfer at which g⁽²⁾ has the maximum oscillation amplitude. b Growth at 216 °C for two different Q_||. The shape of the autocorrelation curve changes at large Q_||, where the maxima become sharp and the minima become broadened. A half-monolayer correlation is observed, which is indicated by dashed lines. An empirical model to fit the data is described in the main text. Note that the upper curve in b is offset by 0.01 for the sake of clarity