J. Phys. I France
Volume 5, Numéro 4, April 1995
Page(s) 443 - 449
DOI: 10.1051/jp1:1995137
J. Phys. I France 5 (1995) 443-449

A Reflection Electron Microscopy Investigation of the Divergence of the Mean Correlated Difference of Step Displacements on a Si(111) Vicinal Surface

J.C. Heyraud, J.M. Bermond, C. Alfonso and J.J. Métois

CRMC2-CNRS, Campus Luminy, Case 913, 13288 Marseille Cedex 09, France

(Received 21 December 1994, accepted 24 January 1995)

A Si(111) vicinal (misorientation $\approx 0.6$) is studied by in situ Reflection Electron Microscopy at 1173 K. A statistical study is done of the distances between pairs of $m^{\rm th}$ neighbours in a step train. The mean correlated difference of the step displacements from their mean positions G(m)=<(ui-ui+m)2> is determined as a function of m. Evidence is given for the roughness of the surface. A logarithmic behaviour of G(mversus  m is demonstrated unambiguously up to m=7. Quantitative agreement is found with the theoretical predictions of Villain, Grempel and Lapujoulade. For more distant pairs of steps a different behaviour is demonstrated: G(m) increases faster than Log (m), a fact already found by another author.

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