Surfactant-modified diffusion on transition-metal surfaces (reprinted with the addition of the appendices)

FEIBELMAN,PETER J. ; KELLOGG,GARY LEE

Sandia National Laboratories

关键词: Removal;    Platinum;    Self-Diffusion;    Carbon Monoxide;    36 Materials Science;   

DOI  :  10.2172/752083
RP-ID  :  SAND99-3061
RP-ID  :  AC04-94AL85000
RP-ID  :  752083

美国|英语

来源: UNT Digital Library

【 摘 要 】

Wanting to convert surface impurities from a nuisance to a systematically applicable nano-fabrication tool, the authors have sought to understand how such impurities affect self-diffusion on transition-metal surfaces. Their field-ion microscope experiments reveal that in the presence of surface hydrogen, self-diffusion on Rh(100) is promoted, while on Pt(100), not only is it inhibited, but its mechanism changes. First-principles calculations aimed at learning how oxygen fosters perfect layerwise growth on a growing Pt(111) crystal contradict the idea in the literature that it does so by directly promoting transport over Pt island boundaries. The discovery that its real effect is to burn off adventitious adsorbed carbon monoxide demonstrates the predictive value of state-of-the-art calculation methods.