solated Fe-57 atoms were studied in MgO single-crystals by emission Mossbauer spectroscopy following implantation of Mn-57 decaying to Fe-57. Four Mossbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

Molholt, T., Mantovan, R., Gunnlaugsson, H., Svane, A., Masenda, H., Naidoo, D., et al. (2014). Interstitial Fe in MgO. JOURNAL OF APPLIED PHYSICS, 115(2) [10.1063/1.4861403].

Interstitial Fe in MgO

FANCIULLI, MARCO;
2014

Abstract

solated Fe-57 atoms were studied in MgO single-crystals by emission Mossbauer spectroscopy following implantation of Mn-57 decaying to Fe-57. Four Mossbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.
Articolo in rivista - Articolo scientifico
Fe, Silicon, defects, Moessbauer, theory
English
2014
115
2
023508
none
Molholt, T., Mantovan, R., Gunnlaugsson, H., Svane, A., Masenda, H., Naidoo, D., et al. (2014). Interstitial Fe in MgO. JOURNAL OF APPLIED PHYSICS, 115(2) [10.1063/1.4861403].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/84224
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