Microsc. Microanal. Microstruct. 8, 167-174 (1997)
DOI: 10.1051/mmm:1997116

An Incommensurate Reconstruction Studied with Scanning Tunnelling Microscopy and Surface X-Ray Diffraction

Bernard Aufray¹, Mats Göthelid¹, Jean-Marc Gay¹, Christine Mottet¹, Erik Landemark², Gerald Falkenberg³, Lars Lottermoser³, Lorenz Seehofer³ et Robert L. Johnson<sup>3

1</sup>  CRMC2-CNRS, Campus de Luminy, Case 913, 13288 Marseille Cedex 9, France
²  Risø National Laboratory, Dept. of Solid State Physics, 4000 Roskilde, Denmark
³  Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany

Abstract
We present the first results of a combined scanning tunneling microscopy (STM) and surface X-ray diffraction (SXRD) study of Ag monolayer deposited on Cu(111). The STM images of Ag monolayer show a periodic frame of triangles, 4 or 5 atomic row wide with 1 or 3 atoms protruding in the centre respectively. Away from the triangles, the corrugation of the atomic rows is about 0.05 A while the depth of the triangles is about 0.5 A. SXRD shows an "average" Ag surface unit cell (9.43 x 9.43) times the Cu(111) surface unit cell without rotation in good agreement with STM observations.

PACS
6820 - Solid surface structure.
6842 - Surface phase transitions and critical phenomena.
6817 - Monolayers and Langmuir Blodgett films.
6845B - Sorption equilibrium at solid fluid interfaces.

Key words
copper -- monolayers -- scanning tunnelling microscopy -- silver -- surface reconstruction -- X ray diffraction -- Ag Cu 111 -- incommensurate reconstruction -- scanning tunnelling microscopy -- surface X ray diffraction -- STM -- XRD -- Ag monolayer -- STM images -- corrugation -- triangles -- surface unit cell -- Cu -- Ag


© EDP Sciences 1997