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

Abstract

The striped structure of the partially oxidized Cu(110) surface has been studied using a novel technique, momentum-resolved electron stimulated desorption ion angular distribution (ESDIAD) Long …O–Cu–O… strings oriented in the 〈001〉 direction and exhibiting attractive interactions with each other form periodically arranged stripes with widths in the nanometer range [D. J. Coulman et al., Phys. Rev. Lett. 64, 1761 (1990); K. Kern et al., ibid. 67, 855 (1991)]. Two different oxygen sites were detected, leading to a twofold symmetrical four-beam O+ ESDIAD pattern with 22° tilting of the beams in the 〈11̄0〉 azimuth (A) direction and 8° in the 〈001〉 azimuth (B) direction. The relative intensities of the four beams have been compared for a wide range of oxygen coverages leading to a model in which the A beams correspond to O+ ions desorbing from the edges of the stripes and the B beams from the internal regions of the stripes. This model is confirmed by studying the effect of the coadsorption of Ar at 32 K on the oxidized structure where the Ar is preferentially adsorbed on the edges 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).