Magnetic properties and microstructure of nanocomposite R2(Fe,Co,Nb)14B/(Fe,Co) (R=Nd, Pr) magnets
Magnetic properties and microstructure of nanocomposite R2(Fe,Co,Nb)14B/(Fe,Co) (R=Nd, Pr) magnets
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纳米复合材料R2(Fe,Co,Nb)14B/(Fe,Co)(R=Nd,Pr)磁体的磁性能和微观结构
DOI：
10.1063/1.369910
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发表时间：
1999
影响因子：
3.2
通讯作者：
B. Ma
中科院分区：
文献类型：
--
作者：
Zhong;Yong Zhang;Yuquan Ding;G. Hadjipanayis;Qun Chen;B. Ma
研究了R8(Fe，Co，Nb)86B6非晶态快淬带晶化制备的R2(Fe，Co，Nb)14B/(Fe，Co)(R=Nd，Pr)纳米复合磁体。研究发现，样品的矫直力主要取决于软相的晶粒度，而软相的晶粒度对样品成分非常敏感。R8Fe86B6的平均晶粒尺寸约为30 nm，但显微组织不均匀，存在多个尺寸在50-100 nm之间的粗大α-Fe颗粒。Nd8Fe86B6和Pr8Fe86B6样品的矫顽力分别为3.3kOe和4.9kOe。Nb掺杂显著减小了α-Fe的晶粒度，提高了矫直力。在Nd8(Fe0.97Nb0.03)86B6和Pr8(Fe0.92Nb0.08)86B6样品中获得的最大矫顽力分别为5.5kOe和9.3kOe。Co替代Fe增大了2：14：1相和α-Fe的晶粒度，显著降低了矫直力。随着Co掺杂样品中B含量的增加，Nd8((Fe0.5Co0.5)0.97Nb0.03)86B6和Pr8((Fe0.5Co0.5)0.94Nb0.06)86B6的矫顽力分别从2.3Koe和2.1Koe部分恢复到4.3Koe和6.5Koe。研究了R8(Fe，Co，Nb)86B6非晶态快淬带晶化制备的R2(Fe，Co，Nb)14B/(Fe，Co)(R=Nd，Pr)纳米复合磁体。研究发现，样品的矫直力主要取决于软相的晶粒度，而软相的晶粒度对样品成分非常敏感。R8Fe86B6的平均晶粒尺寸约为30 nm，但显微组织不均匀，存在多个尺寸在50-100 nm之间的粗大α-Fe颗粒。Nd8Fe86B6和Pr8Fe86B6样品的矫顽力分别为3.3kOe和4.9kOe。Nb掺杂显著减小了α-Fe的晶粒度，提高了矫直力。在Nd8(Fe0.97Nb0.03)86B6和Pr8(Fe0.92Nb0.08)86B6样品中获得的最大矫顽力分别为5.5kOe和9.3kOe。Co替代Fe增大了2：14：1相和α-Fe的晶粒度，显著降低了矫直力。增加钴替代样品中的B含量，可以形成更均匀、更细小的组织，从而使钴的部分回复。
Nanocomposite R2(Fe,Co,Nb)14B/(Fe,Co) (R=Nd, Pr) magnets prepared by crystallizing the as-made R8(Fe,Co,Nb)86B6 amorphous melt-spun ribbons have been studied. The coercivity is found to depend mainly on the grain size of the soft phase which is very sensitive to the sample composition. The average grain size is about 30 nm in R8Fe86B6, but the microstructure is not homogeneous and there are several large α-Fe grains with sizes up to 50–100 nm. The coercivities are 3.3 kOe in Nd8Fe86B6 and 4.9 kOe in Pr8Fe86B6 samples. Nb substitution significantly reduces the grain size of α-Fe and increases the coercivity. The highest coercivities obtained are 5.5 kOe in Nd8(Fe0.97Nb0.03)86B6 and 9.3 kOe in Pr8(Fe0.92Nb0.08)86B6 samples. Co substitution for Fe increases the grain size of both the 2:14:1 phase and α-Fe and dramatically decreases the coercivity. Increasing the B content in Co substituted samples leads to the formation of a more homogeneous and finer microstructure and thus to a partial recovery of the coercivity from 2.3 kOe in Nd8((Fe0.5Co0.5)0.97Nb0.03)86B6 to 4.3 kOe in Nd8((Fe0.5Co0.5)0.97Nb0.03)82B10 and from 2.1 kOe in Pr8((Fe0.5Co0.5)0.94Nb0.06)86B6 to 6.5 kOe in Pr8((Fe0.5Co0.5)0.94Nb0.06)82B10. It is further found that Co substitution improves the temperature dependence of the saturation magnetization.Nanocomposite R2(Fe,Co,Nb)14B/(Fe,Co) (R=Nd, Pr) magnets prepared by crystallizing the as-made R8(Fe,Co,Nb)86B6 amorphous melt-spun ribbons have been studied. The coercivity is found to depend mainly on the grain size of the soft phase which is very sensitive to the sample composition. The average grain size is about 30 nm in R8Fe86B6, but the microstructure is not homogeneous and there are several large α-Fe grains with sizes up to 50–100 nm. The coercivities are 3.3 kOe in Nd8Fe86B6 and 4.9 kOe in Pr8Fe86B6 samples. Nb substitution significantly reduces the grain size of α-Fe and increases the coercivity. The highest coercivities obtained are 5.5 kOe in Nd8(Fe0.97Nb0.03)86B6 and 9.3 kOe in Pr8(Fe0.92Nb0.08)86B6 samples. Co substitution for Fe increases the grain size of both the 2:14:1 phase and α-Fe and dramatically decreases the coercivity. Increasing the B content in Co substituted samples leads to the formation of a more homogeneous and finer microstructure and thus to a partial recovery of the coer...