6533b7d0fe1ef96bd125af4b

RESEARCH PRODUCT

Kinetic model for surface reconstruction

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Institut fu ¨r Physikalische und Theoretische Chemie, Technische Universitat Braunschweig, Hans-Sommer-Strase 10,38106 Braunschweig, Germany~Received 7 December 2001; published 25 July 2002!A microscopic kinetic model for the ab @e.g., hex131 for Pt~100! and 132131 for Pt~110!#surface reconstruction is investigated by means of the mean field approximation and Monte Carlo simulations.It considers homogeneous phase nucleation that induces small surface phase defects. These defects can grow ordecline via phase border propagation in dependence on the chemical coverage by an adsorbate A ~CO!.Anasymmetry in the adsorbate surface diffusion from one surface phase to the other gives rise to two criticalcoverages that determine the intervals of stability of the homogeneous aphase, the dynamically stable het-erogeneous state, and the homogeneous b phase. Both surfaces show a very similar qualitative behaviorregarding the phase transitions that are of second order in both cases. As a result the experimentally observednonlinear island growth rate and the critical coverages can be explained at a quantitative level.DOI: 10.1103/PhysRevE.66.011603 PACS number~s!: 82.65.1r, 64.60.Qb, 81.10.Jt, 82.20.WtI. INTRODUCTION