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简要回顾了20世纪20年代以来我国现代磁学研究的历史。20世纪80年代初期正值我国改革开放浪潮之时,科技人员纷纷走上科技成果产业化道路。建立于1985年的中国科学院三环公司就是一个成功的代表,同时好也是我国现代磁学研究结出的一颗硕果。 相似文献
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本文对Nd-Fe-Si三元系富铁区域相的结构和磁性进行了研究。结果表明,Nd-Fe-Si三元系富铁区域(Fe>40at%),除出现NdFe2Si2三元金属间化合物外(Si>20at%),同时只出现Nd2(Fe,Si)17赝二元金属间化合物,其中Si取代9d位的Fe原子,而不能形成类似于Nd2Fe14B的三元金属间化合物,Si取代Nd2Fe17中的9d位Fe原子后,使晶胞体积缩小;使饱和磁化强度减小;同时使Fe次晶格的铁磁相互作用增强,导致居里温度增高;还使得Fe次晶格的易面各向异性减弱,造成室温下各向异性场减小。
关键词: 相似文献
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本文对R_(13)Fe_(74)Si_(13)(R=Ce,Pr,Nd,Gd,Tb,Dy,Ho,Er,Y)三元合金的结构和磁性进行了研究。结果表明,R_(13)Fe_(74)Si_(13)的主相为R_2(Fe_(0.85)Si_(0.15)_(17)赝二元金属间化合物,而不出现类似于R_2Fe_(14)B的三元金属间化合物。Si原子可能择优取代R_2Fe_(17)中的Fe原子(Th_2Zn_(17)中的9d位或Th_2Ni_(17)中的6g位)。R_(13)Fe_(74)Si_(13)的居里温度比相应的R_2Fe_(17)有所提高。观察了R_(13)Fe_(74)Si_(13)的饱和磁化强度以及室温下的各向异性。本文还从多晶样品磁矩变化模型,根据提拉样品法的低温测量结果,初步定性地分析了R_(13)Fe_(74)Si_(13)低温下磁结构的变化。 相似文献
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The novel Gd3(Fe0.978Ti0.022)29 compounds and their nitride have been synthesized. The X-ray diffraction patterns of the Gd3(Fe,Ti)29Ny and its parent compounds were indexed in the Nd3(Fe,Ti)29-type structure with a monoclinic symmetry and space group P21/c, Both the nitride and the parent compounds exhibit ferrimagnetlc coupling. Nitrogenatio led to an increase in Curie temperature and saturation magnetization. The Curie temperatures are 517K for the parent and 765K for the nitride. The saturation magnetizations σs at 4.2K are 101.9A·m2/kg for the parent and 128A·m2/kg for the nitride. Both the nitride and parent exhibit a planar anisotropy. Nitrogenation led to a decrease of the contribution of Fe-sublattice to planar anisotropy. The anisotropy fields at 4.2K are 9.8T for the parent and 6.5 T for the nitride. 相似文献
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在烧结Nd-Fe-B中,各种相的形成,添加元素原子的替代、对磁体的微结构和性能的影响以 及大多数工艺与热力学都有密切联系.Al,Cu,Ga,Sn,Zn等与B均具有正的混合焓,在主相 中的浓度都很低,与富 Nd相反应改善磁体的微结构. Zi,Ti,Nb,W,Mo,V等与Nd有很大的 正的混合焓,与B具有很大的负的混合焓,能优化磁体的微结构和稀释磁体.参考热力学,系 统讨论了各种常用添加元素对烧结Nd-Fe-B的微结构、性能和制造工艺的影响.
关键词:
Nd-Fe-B永磁体
混合焓
烧结 相似文献
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The novel Gd3(Fe0.978Ti0.022)29 compounds and their nitride have been synthesized. The X-ray diffraction patterns of the Gd3(Fe,Ti)29Ny and its parent compounds were indexed in the Nd3(Fe,Ti)29-type structure with a monoclinic symmetry and space group P21/c, Both the nitride and the parent compounds exhibit ferrimagnetlc coupling. Nitrogenatio led to an increase in Curie temperature and saturation magnetization. The Curie temperatures are 517K for the parent and 765K for the nitride. The saturation magnetizations σs at 4.2K are 101.9A·m2/kg for the parent and 128A·m2/kg for the nitride. Both the nitride and parent exhibit a planar anisotropy. Nitrogenation led to a decrease of the contribution of Fe-sublattice to planar anisotropy. The anisotropy fields at 4.2K are 9.8T for the parent and 6.5 T for the nitride. 相似文献
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The crystallographic and magnetic structures of Nd2Fe17Nx(x = 2.5, 3.0, 5.5) at room temperature were refined by Rietveld analysis of neutron powder diffraction data. We found that Nd2Fe17Nx has a Th2Zn17 type structure (S.G. R3m) and the nitrogen atoms occupy both 9e and 18g sites simultaneously and at different rates. 相似文献