Distinguishing step relaxation mechanisms via pair correlation functions

Dougherty, Daniel B.; Lyubinetsky, Igor; Einstein, T. L.; Williams, Ellen D.

doi:10.1103/physrevb.70.235422

Cited by 10 publications

(13 citation statements)

References 32 publications

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“…Note that one can also distinguish EC from DSS by a careful examination of step correlations, as described in Ref. 50. In that case, steps on the Si͑111͒-ͱ 3 ϫ ͱ 3R30°Al surface at 970 K were shown to have an EC rather than a DSS behavior.…”

Section: B Temporal Correlationsmentioning

confidence: 98%

Step line tension and step morphological evolution on the Si(111)(1×1)surface

et al. 2008

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The temperature dependence of the step line tension on the Si͑111͒ ͑1 ϫ 1͒ surface is determined from a capillary wave analysis of two-dimensional island edge fluctuations and straight step fluctuations that are observed with low energy electron microscopy. The line tension decreases by nearly 20% with a linear temperature coefficient of −0.14 meV/ Å K between 1145 and 1233 K. Temporal correlations of step fluctuations exhibit the distinctive signature in the wavelength dependence of the relaxation time of a terrace diffusion-limited mechanism for step motion. We also find that the role of desorption in island decay increases dramatically in the temperature range ͑1145-1380 K͒ that island decay is studied. Consequently, we generalize the current quasistatic model of island decay to take account of desorption. The evaluation of the island decay time with this model referenced to the temperature-dependent line tension accurately determines activation energies that are relevant to mass transport and sublimation.

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Section: B Temporal Correlationsmentioning

confidence: 98%

Step line tension and step morphological evolution on the Si(111)(1×1)surface

et al. 2008

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“…step position vs. time) on Ag thin films over a temperature range for which the time scale of the physical fluctuations varies dramatically [2][3][4][5][6]. We also consider similar issues of correlation length and measurement time for fluctuations of steps on Al-terminated Si(111), for which the physical mechanism underlying the step fluctuations is different [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Correlation time for step structural fluctuations

et al. 2005

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Time dependent STM has been used to evaluate step fluctuations as a function of temperature (300-450 K) on Ag(111) films grown on mica. The temporal correlation function scales as a power law in time, t 1/n with measured values of 1/n varying over a range of 0.19 ± 0.04 to 0.29 ± 0.04 with no correlation on temperature. The average value of 1/n = 0.24 ± 0.01 is consistent with step-edge diffusion limited fluctuations (n = z = 4, conserved noise). The magnitude of the time correlation function and the width of the fluctuations both scale with temperature with the same apparent activation energy of E eff = 0.21 ± 0.02 eV, indicating that the correlation time is at most weakly temperature dependent. Direct analysis of the autocorrelation function confirms that the correlation time is at most weakly temperature dependent, and thus the apparent correlation length is strongly temperature dependent. This behavior can be reproduced by assuming that the apparent correlation length is governed by the longest wavelength of step fluctuations that can be sampled in the measurement time interval. Evaluation of the correlation time for previous measurements for Al/Si(111) ( z =2) yields the same conclusion about measurement time interval. In both cases the ratio of the measurement time to the effective correlation time is on the order of 10.

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“…The most straightforward interpretation of this signature is that the fluctuations result from mass exchange randomly from all step edge positions with the neighboring terraces. Alternative explanations [19][20][21] based on diffusion limited kinetics are rendered less tenable in this case by the experimental cross correlation signature 22 and the observation of temporal persistence behavior consistent with z = 2 23 . If the observations are due to random mass exchange, these dynamics fall within the Edwards-Wilkinson model, which can be described by the equation…”

Section: Introductionmentioning

confidence: 99%