Mössbauer Spectroscopy and X-Ray Diffraction Studies of the Phase Composition of Crystallized NdxFe81.5-xB18.5 Alloys with 7 ≤ x ≤15
CHENG Zhao-hua1, SHEN Bao-gen1, ZHANG Jun-xian1, MAO Ming-xi, SUN Ji-jun, YANG Chun-li, LI Fa-shen, ZHANG Yi-de
1State Key Laboratory of Magnetism, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080
Department of Physics, Lanzhou University, Lanzhou 730000
Mössbauer Spectroscopy and X-Ray Diffraction Studies of the Phase Composition of Crystallized NdxFe81.5-xB18.5 Alloys with 7 ≤ x ≤15
1State Key Laboratory of Magnetism, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080
Department of Physics, Lanzhou University, Lanzhou 730000
Abstract： The phase composition of melt-spun Nd-Fe-B with intermediate and high Nd concentrations has been studied by Mössbauer effect. Based on the knowledge of the 57Fe hyperfine parameters for Nd2Fe14B, Nd2Fe23B3, and Nd1.1Fe4B4, the phases produced during annealing Nd-Fe-B amorphous alloys can be identified. It is found that the NdxFe81.5-xB18.5 samples with 7≤ x ≤ 9 contain the Nd2Fe23B3 metastable phase and the Nd1.1Fe4B4 paramagnetic phase. The body-centered-cubic structure of Nd2Fe23B3 cannot generate the hard magnetic properties. The samples with 12 ≤ x ≤ 15 consist of the Nd2Fe14B hard magnetic phase and the Nd1.1Fe4B4 paramagnetic phase. The large coercivity for the high Nd content Nd-Fe-B originates from the very fine size of Nd2Fe14B grains below the particle size of the single domain, which may contribute to a pinning effect of domain wall.
CHENG Zhao-hua;SHEN Bao-gen;ZHANG Jun-xian;MAO Ming-xi;SUN Ji-jun;YANG Chun-li;LI Fa-shen;ZHANG Yi-de. Mössbauer Spectroscopy and X-Ray Diffraction Studies of the Phase Composition of Crystallized NdxFe81.5-xB18.5 Alloys with 7 ≤ x ≤15[J]. 中国物理快报, 1997, 14(5): 387-390.
CHENG Zhao-hua, SHEN Bao-gen, ZHANG Jun-xian, MAO Ming-xi, SUN Ji-jun, YANG Chun-li, LI Fa-shen, ZHANG Yi-de. Mössbauer Spectroscopy and X-Ray Diffraction Studies of the Phase Composition of Crystallized NdxFe81.5-xB18.5 Alloys with 7 ≤ x ≤15. Chin. Phys. Lett., 1997, 14(5): 387-390.
1997, Vol. 14 
