PNNL

Abstract

Step edge fluctuations on a multi-component surface of Al/Si(111)-( ) were measured via scanning tunneling microscopy over a temperature range of 720K-1070K, for step lengths of 65-160 nm. Even though the time scale of fluctuations of steps on this surface varies by orders of magnitude over the indicated temperature ranges, measured first-passage spatial persistence and survival probabilities are shown to be temperature independent over the temperature and spatial range. The power law functional form for spatial persistence probabilities is confirmed and the spatial persistence exponent is measured to be 0.71 ± 0.13 in contrast to theoretical predictions of a value = ½. The survival probability is found to scale directly with x/L, where x is the step edge displacement and L is the step length anallyzed, with minor corrections for the discrete measurement interval. The form of the survival agrees quantitatively with theoretical predictions, which reduce to an exponential decay at short distances (x/L