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Abstract

Step structure and dynamics and adsorbate-induced reconstruction of stepped surfaces are useful features for investigating fundamental surface phenomena and their practical consequences. In this respect, vicinal copper(11n) surfaces with n=3, 5 and 9 were studied by scanning tunnelling microscopy (STM) at 300ºK. While the regular monoatomic steps fluctuate for copper(119), they are apparently stabilised for n\leq5 by their strong repulsive interaction and this leads to a very low kink activity. In addition to the regular steps, the formation of double steps was observed as a particular phenomenon on those surfaces. These double steps determine the dynamic behaviour at room temperature. By applying existing models for the fluctuations of the step positions in space and time, the formation energy for kinks at these double steps was determined to be 0.16eV for copper(115). According to this evaluation, diffusion along step edges is the dominating mass-transport mechanism. A model for the structure of the double steps and for the atomic displacement processes necessary for kink migration at these steps is presented. Complete faceting is observed for these surfaces upon oxygen adsorption at elevated temperatures (around 500ºK) and was studied in detail for n=5 and 9. Both surfaces reconstruct into two types of {104} facets and a third facet, the orientation of which is determined by the macroscopic crystal orientation. The facet size is governed by the formation kinetics and can be controlled by varying the crystal temperature or the oxygen partial pressure.

Additional information

Authors: REINECKE N ET AL, Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching (DE)
Bibliographic Reference: An article published in: Applied Physics A, Volume 75, Issue 1, (2002), pp 1-10.
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://link.springer.de/link/service/journals/00339/tocs/t2075001.htm
Record Number: 200214949 / Last updated on: 2002-07-09
Category: PUBLICATION
Original language: en
Available languages: en