Vibrational spectroscopy of oxygen on the (100) and (111) surfaces of lanthanum hexaboride

Thomas Yorisaki, Aashani Tillekaratne, Yukihiro Moriya, Chuhei Oshima, Shigeki Otani, Michael Trenary

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Reflection absorption infrared spectroscopy (RAIRS) and high resolution electron energy loss spectroscopy (HREELS) have been used to study the adsorption of oxygen on the (100) and (111) surfaces of lanthanum hexaboride. Exposure of the surface at temperatures of 95 K and above to O2 produces atomic oxygen on the surface and yields vibrational peaks in good agreement with those observed in previous HREELS studies. On the La-terminated (100) surface, RAIRS peaks correspond to vibrations of the boron lattice that gain intensity due to a decrease in screening of surface dipoles that accompanies oxygen adsorption. A sharp peak at ∼ 734 cm-1 in the HREEL spectrum shows isotopic splitting with RAIRS into two components at 717 and 740 cm-1 with full widths at half maxima of only 12 cm-1. The sharpness of this mode is consistent with its interpretation as a surface phonon that is well separated from both the bulk phonons and other surface phonons of LaB6. On the boron-terminated LaB6(111) surface, broad and weak features are assigned to both vibrations of the boron lattice and of boron oxide. On the (100) surface, oxygen blocks the adsorption sites for CO, and adsorbed CO prevents the dissociative adsorption of O2.

Original languageEnglish
Pages (from-to)1202-1207
Number of pages6
JournalSurface Science
Volume604
Issue number13-14
DOIs
Publication statusPublished - 2010 Jul 15

Keywords

  • High resolution electron energy loss spectroscopy
  • Lanthanum hexaboride
  • Oxygen
  • Reflection absorption infrared spectroscopy
  • Surface vibrational spectroscopy

ASJC Scopus subject areas

  • Surfaces and Interfaces
  • Condensed Matter Physics
  • Materials Chemistry
  • Surfaces, Coatings and Films

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    Yorisaki, T., Tillekaratne, A., Moriya, Y., Oshima, C., Otani, S., & Trenary, M. (2010). Vibrational spectroscopy of oxygen on the (100) and (111) surfaces of lanthanum hexaboride. Surface Science, 604(13-14), 1202-1207. https://doi.org/10.1016/j.susc.2010.04.003