A scanning tunnelling microscopy study of C and N adsorption phases on the vicinal Ni(100) surfaces Ni(810) and Ni(911)

SURFACE SCIENCE

卷:646

Article

Driver, S. M.^1,2  Toomes, R. L.¹  Woodruff, D. P.¹ 

[1] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England

[2] Univ Cambridge, Dept Chem, Lensfield Rd, Cambridge CB2 1EW, England

关键词: Surface structure;    Stepped surfaces;    Nickel;    Carbon;    Nitrogen;   

DOI  :  10.1016/j.susc.2015.06.006

来源: Elsevier

【 摘 要 】

The influence of N and C chemisorption on the morphology and local structure of nominal Ni(810) and Ni(911) surfaces, both vicinal to (100) but with [001] and [01 (1) over bar] step directions, respectively, has been investigated using scanning tunnelling microscopy (STM) and low energy electron diffraction. Ni(911) undergoes substantial step bunching in the presence of both adsorbates, with the (911)/N surface showing (411) facets, whereas for Ni(810), multiple steps 2-4 layers high are more typical. STM atomic-scale images show the (2 x 2)pg 'clock' reconstruction on the (100) terraces of the (810) surfaces with both C and N, although a second c(2 x 2) structure, most readily reconciled with a 'rumpling' reconstruction, is also seen on Ni(810)/N. On Ni(911), the clock reconstruction is not seen on the (100) terraces with either adsorbate, and these images are typified by protrusions on a (1 x 1) mesh. This absence of clock reconstruction is attributed to the different constraints imposed on the lateral movements of the surface Ni atoms adjacent to the up-step edge of the terraces with a [01 (1) over bar] step direction. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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