Effects of random distribution of Mn,Fe in Co2Mn1−xFexSi Heusler compounds probed by Mn55 nuclear magnetic resonance

Sabine Wurmehl, Jürgen T. Kohlhepp, Henk J. M. Swagten, Bert Koopmans, Marek Wójcik, Benjamin Balke, Christian G. F. Blum, Vadim Ksenofontov, Gerhard H. Fecher, Claudia Felser
2008 Journal of Applied Physics  
Wurmehl, S.; Kohlhepp, J.T.; Swagten, H.J.M.; Koopmans, B.; Wójcik, M.; Balke, B.; Blum, C.G.F.; Ksenofontov, V.; Fecher, G.H.; Felser, C. Recent spin echo nuclear magnetic resonance ͑NMR͒ revealed that the half-metallic Co 2 Mn 1−x Fe x Si Heusler alloys exhibit the L2 1 structure with random distribution of Mn and Fe on the 4b Wyckoff position. This random distribution is most prominent in the third coordination shell of the 55 Mn nuclei, as this shell is the first magnetically active shell,
more » ... ally active shell, leading to a line splitting in the 55 Mn NMR spectra. A comparison, as presented in this paper, of all 55 Mn NMR satellite lines shows that the resonance frequencies corresponding to the same number of Fe atoms in the third shell of 55 Mn shift to slightly different resonance frequencies with increasing overall Fe content x. This shift is related to the constructive contribution of higher shells to the hyperfine field. These higher shells affect also the satellite linewidth, leading to a parabolic behavior with increasing Fe concentration x. This parabolic behavior is modified by the frequency spacing related to the replacement of Mn by Fe.
doi:10.1063/1.2831359 fatcat:lnlnnavq3beyppuk6yv62wv3e4