1. Neutron diffraction and Mössbauer spectral study of Nd2Fe16Ti and its nitride
- Author
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Fernande Grandjean, M. Ellouze, Peter C. Ezekwenna, Oran Allan Pringle, H. Luo, Gary J. Long, William B. Yelon, and Ph. L'Héritier
- Subjects
Crystallography ,Materials science ,Lattice constant ,Mössbauer effect ,Rietveld refinement ,Neutron diffraction ,Mössbauer spectroscopy ,General Physics and Astronomy ,Dumbbell ,Nitride ,Hyperfine structure - Abstract
The 295 K powder neutron diffraction patterns and the temperature dependence of the Mossbauer spectra of Nd2Fe17−xTix and Nd2Fe17−xTixNy have been measured. A Rietveld refinement of the neutron diffraction patterns yields the Nd2Fe16.32Ti0.68 and Nd2Fe16.32Ti0.68N2.7 stoichiometries for the two compounds and indicates that titanium occupies only the 6c crystallographic site and nitrogen only the 9e site in the rhombohedral Th2Zn17 structure. The insertion of interstitial nitrogen into Nd2Fe16.32Ti0.68 produces a 6.8% increase in the unit cell volume. The relative areas of the Mossbauer spectral components indicate that iron–iron, iron–titanium, and titanium–titanium 6c–6c dumbbell pairs exist in both of these materials. The magnetic hyperfine fields observed for the iron on the 6c site in the iron–titanium dumbbell pair in both compounds is substantially reduced from that found in Nd2Fe17 and Nd2Fe17N2.6 because of the titanium dumbbell near neighbor. For all the remaining hyperfine parameters there is a ...
- Published
- 1998