Surface properties of SmB6 from x-ray photoelectron spectroscopy

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • N. Heming - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • U. Treske - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • M. Knupfer - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • B. Buechner - , Institute of Solid State and Materials Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • D. S. Inosov - , Institute of Solid State and Materials Physics (Author)
  • N. Y. Shitsevalova - , National Academy of Sciences of Ukraine (Author)
  • V. B. Filipov - , National Academy of Sciences of Ukraine (Author)
  • S. Krause - , Medical Physics (Author)
  • A. Koitzsch - , Leibniz Institute for Solid State and Materials Research Dresden (Author)

Abstract

We have investigated the properties of cleaved SmB6 single crystals by x-ray photoelectron spectroscopy. At low temperatures and freshly cleaved samples a surface core level shift is observed which vanishes when the temperature is increased. A Sm valence between 2.5 and 2.6 is derived from the relative intensities of the Sm2+ and Sm3+ multiplets. The B/Sm intensity ratio obtained from the core levels is always larger than the stoichiometric value. Possible reasons for this deviation are discussed. The B 1s signal shows an unexpected complexity: An anomalous low energy component appears with increasing temperature and is assigned to the formation of a suboxide at the surface. While several interesting intrinsic and extrinsic properties of the SmB6 surface are elucidated in this manuscript, no clear indication of a trivial mechanism for the prominent surface conductivity is found.

Details

Original languageEnglish
Article number195128
Number of pages7
JournalPhysical Review B
Volume90
Issue number19
Publication statusPublished - 17 Nov 2014
Peer-reviewedYes

External IDs

Scopus 84911439989

Keywords

Keywords

  • TRANSPORT, SPECTRA, VALENCE, STATES, BORON, GAP

Library keywords