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Topics in Catalysis

, Volume 18, Issue 1–2, pp 9–14 | Cite as

Structural, Thermal and Magnetic Properties of Thin Metal Films and Adsorbate–Substrate Systems Studied by XAFS and XMCD

  • Toshihiko Yokoyama
  • Toshiaki Ohta
Article

Abstract

Thin metal films often exhibit interesting properties that are essentially different from the bulk ones. XAFS (X-ray absorption fine structure) and XMCD (X-ray magnetic circular dichroism) techniques are quite suitable to investigate structural, thermal and magnetic properties of thin metal films. In this proceeding, we will present following two topics concerning structural and magnetic properties of adsorbates on thin metal films. The first one is the adsorption geometry of SO2 on a 1-monolayer (ML) Pd thin film grown on a Ni(111) single crystal. It was found by S K-edge XAFS that SO2 is lying flat on 1-ML Pd/Ni(111). This result is not similar to the bulk Pd surface but to the bulk Ni one. This finding indicates significant modification of the electronic structure of the 1-ML Pd film compared to the bulk one. The second topic is the magnetic moment induced on CO adsorbed on Ni epitaxial films grown on Cu(001). The O K-edge XMCD results revealed that in the perpendicularly magnetized 10-ML Ni film the orbital moment of CO is parallel to the substrate Ni magnetization, while it is antiparallel in the in-planar magnetized 6-ML and thick (>100 ML) films. The origin of the induced orbital moment at CO is discussed.

X-ray absorption fine structure (XAFS) X-ray magnetic circular dichroism (XMCD) epitaxial film SO2 surface structure molecular orientation CO magnetic anisotropy orbital magnetic moment 

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Copyright information

© Plenum Publishing Corporation 2002

Authors and Affiliations

  • Toshihiko Yokoyama
    • 1
  • Toshiaki Ohta
    • 1
  1. 1.Department of Chemistry, Graduate School of ScienceThe University of TokyoBunkyo-ku, TokyoJapan

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