M{umlt o}ssbauer and x-ray diffraction studies of the phase composition of crystallized Nd{sub {ital x}}Fe{sub 81.5{minus}{ital x}}B{sub 18.5} alloys with 7{le}{ital x}{le}16 (abstract)
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, Peoples Republic of (China)
- Department of Physics, Lanzhou University, Peoples Republic of (China)
In previous work, the phase composition of melt-spun Nd-Fe-B with a low Nd concentration ({ital X}{le}6 at.{percent}) have been extensively investigated by means of x-ray diffraction, spin echo nuclear magnetic resonance, and M{umlt o}ssbauer spectra. However, the phase composition of melt-spun Nd-Fe-B with intermediate and high Nd concentration has not been studied by M{umlt o}ssbauer effect. Based on the knowledge of the {sup 57}Fe hyperfine parameters for Nd{sub 2}Fe{sub 14}B, Nd{sub 1.1}Fe{sub 4}B{sub 4} and Nd{sub 2}Fe{sub 23}B{sub 3}, the phases produced during annealing Nd-Fe-B amorphous alloys can be identified with greater sensitivity by M{umlt o}ssbauer spectroscopy than by x-ray diffraction. In the present work, a combination of x-ray diffraction experiments and M{umlt o}ssbauer spectroscopy has been performed on annealed Nd{sub {ital x}}Fe{sub 81.5}B{sub 18.5} (7{le}{ital x}{le}16). It is found that the samples with 7{le}{ital x}{le}9 contain Nd{sub 2}Fe{sub 23}B{sub 3} metastable phase and Nd{sub 1.1}Fe{sub 4}B{sub 4} paramagnetic phase. The body-centered-cubic structure of Nd{sub 2}Fe{sub 23}B{sub 3} cannot generate the hard magnetic properties. The samples with 12{le}{ital x}{le}16 consist of Nd{sub 2}Fe{sub 14}B magnetically hard phase and Nd{sub 1.1}Fe{sub 4}B{sub 4} paramagnetic phase. The large coercivity for the high Nd content Nd-Fe-B originates from the very fine size of Nd{sub 2}Fe{sub 14}B crystallites below the critical size of single domain particle, which has a pinning domain wall effect. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 280067
- Report Number(s):
- CONF-951101--
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 79; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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