The shifted row reconstruction of PtxNi1-x(100)

M. Schmid, A. Biedermann, S. D. Böhmig, P. Weigand and P. Varga

Institut für Allgemeine Physik, Technische Universität Wien, A-1040 Wien, Austria

Surf. Sci. 318 (1994) 289-298

Scanning tunneling microscopy on Pt10Ni90(100) and Pt25Ni75(100) single crystals reveals close-packed rows of atoms, which are shifted by 1/4 <110> along the direction of the rows into a bridge position and slightly outward of the surface. Maximum entropy deconvolution of atomically resolved STM data shows that all atoms between the shifted rows are close to the unreconstructed positions. The density of the shifted rows increases with increasing Pt surface concentration up to a maximum value of each 5th row shifted. The reconstruction shows little dependence on the carbon contamination of the surface, but it is lifted by a full c(2 × 2) coverage of carbon monoxide, which can be imaged simultaneously with the substrate, indicating an on-top position of CO. The driving force of the shifted row reconstruction is discussed.

Corresponding author: M. Schmid (schmid< encoded email address >).

Part of this work is on display in the IAP/TU Wien STM Gallery (see the reconstructions page).