Hyperfine Interactions

, Volume 198, Issue 1, pp 5–13

Mössbauer spectroscopy of 57Fe in α-Al2O3 following implantation of 57Mn*

  • H. P. Gunnlaugsson
  • R. Mantovan
  • T. E. Mølholt
  • D. Naidoo
  • K. Johnston
  • H. Masenda
  • K. Bharuth-Ram
  • G. Langouche
  • S. Ólafsson
  • R. Sielemann
  • G. Weyer
  • Y. Kobayashi
  • the ISOLDE collaboration
Article

DOI: 10.1007/s10751-010-0184-5

Cite this article as:
Gunnlaugsson, H.P., Mantovan, R., Mølholt, T.E. et al. Hyperfine Interact (2010) 198: 5. doi:10.1007/s10751-010-0184-5
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Abstract

The valence state and annealing reactions of Mn/Fe in single crystalline α-Al2O3 have been determined following low fluence (<1012 cm − 2) 60 keV implantations of 57Mn +  (T1/2 = 1.5 min) and emission Mössbauer spectroscopy on the 57mFe daughter nuclei in the temperature range from 110–700 K. At 110 K, most probe atoms are found in the Fe2 +  state in amorphous surroundings due to the implantation damage. A fraction of the Fe is found in cubic environment, possibly nano-precipitates of η-Al2O3. This site is found to disappear from the spectra above 500 K. Annealing of the damage sites at increasing temperatures leads first to increased incorporation of the probe atoms as Fe3 +  on Al sites, and, above room temperature, also as Fe4 + . The Fe3 +  sub-spectrum is masked by slow paramagnetic relaxations following a T2 dependence, as expected for a two-phonon Raman process. Our data is consistent with data from 57Co and 57Fe implantations, suggesting a general increase in the average Fe valence state with lower implantation dose and negligible annealing reactions at room temperature.

Keywords

Emission Mössbauer spectroscopyAl2O357Fe57Mn

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • H. P. Gunnlaugsson
    • 1
  • R. Mantovan
    • 2
  • T. E. Mølholt
    • 3
  • D. Naidoo
    • 4
  • K. Johnston
    • 5
  • H. Masenda
    • 4
  • K. Bharuth-Ram
    • 6
  • G. Langouche
    • 7
  • S. Ólafsson
    • 3
  • R. Sielemann
    • 8
  • G. Weyer
    • 1
  • Y. Kobayashi
    • 9
  • the ISOLDE collaboration
    • 5
  1. 1.Department of Physics and AstronomyAarhus UniversityÅrhus CDenmark
  2. 2.Laboratorio MDM, IMM-CNRAgrate BrianzaItaly
  3. 3.Science InstituteUniversity of IcelandReykjavíkIceland
  4. 4.School of PhysicsUniversity of the WitwatersrandWITSSouth Africa
  5. 5.PH Dept, ISOLDE/CERNGeneva 23Switzerland
  6. 6.School of PhysicsUniversity of KwaZulu-NatalDurbanSouth Africa
  7. 7.Instituut voor Kern- en StralingsfysicaUniversity of LeuvenLeuvenBelgium
  8. 8.Helmholtz-Zentrum Berlin für Materialien und EnergieBerlinGermany
  9. 9.The Institute of Physical and Chemical Research (RIKEN)SaitamaJapan