X-ray photoelectron diffraction study of the reconstructed Ni(110)-1 × 2-H surface
1992; Elsevier BV; Volume: 277; Issue: 1-2 Linguagem: Inglês
10.1016/0039-6028(92)90618-g
ISSN1879-2758
AutoresO. Knauff, U. Grosche, D.A. Wesner, H.P. Bonzel,
Tópico(s)Advanced Chemical Physics Studies
ResumoAbstract Hydrogen-induced reconstruction of Ni(110) was studied by X-ray photoelectron diffraction (XPD) in the polar angle (θ) scanning mode. The angle-resolved emission of Ni 2p and Ni 3p photoelectrons along the [001] and [110] azimuths for the 1 × 1 and the reconstructed 1 × 2-H surface of Ni(110) was measured at 120 K. The XPD patterns showed intensity differences, Δ I rec (θ) = I (θ, 1 × 2)- I (θ, 1 × 1), which are characteristic of the reconstruction process. These differences, amounting to about 8% of the minimum intensity in a single distribution, exhibit positive and negative excursions for the [001] azimuth. The maxima in Δ I rec are frequently observed at the same angles where minima exist in I (θ), and minima in Δ I rec correlate with maxima in I (θ). These changes are attributed to altered forward scattering and diffraction directions, elastic diffuse and inelastic scattering (attenuation), all due to the shifting of near-surface atoms. The differences Δ I rec for the [110] azimuth are negative over the whole range of polar angles indicative of elastic diffuse scattering and inelastic damping of the bulk forward scattering peaks. Single scattering cluster calculations for the 1 × 1- and 1 × 2-H-Ni(110) surface are compared with the experimental results; the intensity differences are approximately consistent with a row-pairing reconstruction.
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