Dynamics of the striped nanostructure of the oxidized Cu(110) surface: A momentum resolved electron stimulated desorption ion angular distribution study

The striped structure of the partially oxidized Cu(110) surface-has been st udied using a novel technique, momentum-resolved electron stimulated desorp tion ion angular distribution (ESDIAD) Long O-...-Cu-O-.... strings oriente d in the (001) direction and exhibiting attractive interactions with each o ther form periodically arranged stripes with widths in the nanometer range [D.. J. Coulman et at., Phys. Rev. Lett. 64, 1761 (1990); K. Kern et al., i bid. 67, 855 (1991)]. Two different oxygen sites were detected, leading to a twofold symmetrical four-beam O+ ESDIAD pattern-with 22 degrees tilting o f the beams in the (1 (1) over bar 0) azimuth (A) direction and 8 degrees i n the (001)azimuth (B)direction. The relative intensities of the four beams have been compared for a wide range of oxygen coverages leading to st mode l in which the A beams correspond to O+ ions desorbing from-the edges of th e stripes and the B beams from the internal regions of the stripes. This mo del is confirmed by studying the effect of the coadsorption of Ar at 32 K o n the oxidized structure-where the Ar is preferentially adsorbed on the edg es of the stripes. The dynamical motion of the one-dimensional O-...-Cu-O-. .. oscillator chains situated at the edges of the stripes has been studied by momentum-resolved ESDIAD measurements over a broad range of temperatures (80-650 K). (C) 1999 American Vacuum Society. [S0734-2101(99)13304-9].