In:
Journal of Applied Physics, AIP Publishing, Vol. 79, No. 8 ( 1996-04-15), p. 5709-5709
Abstract:
In previous work, the phase composition of melt-spun Nd-Fe-B with a low Nd concentration (X≤6 at. %) have been extensively investigated by means of x-ray diffraction, spin echo nuclear magnetic resonance, and Mössbauer spectra. However, the phase composition of melt-spun Nd-Fe-B with intermediate and high Nd concentration has not been studied by Mössbauer effect. Based on the knowledge of the 57Fe hyperfine parameters for Nd2Fe14B, Nd1.1Fe4B4 and Nd2Fe23B3, the phases produced during annealing Nd-Fe-B amorphous alloys can be identified with greater sensitivity by Mössbauer spectroscopy than by x-ray diffraction. In the present work, a combination of x-ray diffraction experiments and Mössbauer spectroscopy has been performed on annealed NdxFe81.5B18.5 (7≤x≤16). It is found that the samples with 7≤x≤9 contain Nd2Fe23B3 metastable phase and Nd1.1Fe4B4 paramagnetic phase. The body-centered-cubic structure of Nd2Fe23B3 cannot generate the hard magnetic properties. The samples with 12≤x≤16 consist of Nd2Fe14B magnetically hard phase and Nd1.1Fe4B4 paramagnetic phase. The large coercivity for the high Nd content Nd-Fe-B originates from the very fine size of Nd2Fe14B crystallites below the critical size of single domain particle, which has a pinning domain wall effect.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
1996
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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