Enhanced coercivity in REFeAl-based bulk amorphous alloys
Enhanced coercivity in REFeAl-based bulk amorphous alloys
复制标题
DOI：
10.1063/1.1558250
复制
发表时间：
2003-05
影响因子：
3.2
通讯作者：
I. Betancourt;R. Valenzuela
中科院分区：
文献类型：
--
作者：
I. Betancourt;R. Valenzuela
系统地研究了压铸稀土铁铝(RE=Nd+Pr)块体非晶合金中添加少量的B、Cu和Dy。差示扫描量热仪和X射线衍射仪的数据与B、Cu+B-和Dy合金的非晶态组织和少量的HCP-Nd型微晶相一致。对于B、B+Cu和Dy的添加，Hc显示出逐渐增强的趋势(从Nd30Fe60Al10的284kA/m增加到Dy替代合金的388kA/m)。Hc的改善不仅与磁化壁钉扎在微晶上有关，而且还与形核位置的增加有关，从而与RE和RE-Fe-Al团簇的数量有关。与后者一致的是，在451K以上，所有合金成分都观察到了以团簇结构为特征的超顺磁性行为。
A systematic study of die-cast REFeAl (RE=Nd+Pr) bulk amorphous alloys with small B, Cu, and Dy additions is presented. Differential scanning calorimetry and x-ray diffraction data are consistent with an amorphous microstructure and a small amount of hcp Nd-type crystallites embedded in the amorphous matrix for B, Cu+B-, and Dy-containing alloys. Coercivity, Hc, exhibits a progressive enhancement upon B, B+Cu, and Dy addition (from 284 kA/m for Nd30Fe60Al10 up to 388 kA/m for Dy substituted alloy). This Hc improvement is associated not only with domain wall pinning on the crystallites, but also with the increase of nucleation sites and thus, with the number of RE and RE–Fe–Al clusters. In agreement with the latter, a superparamagnetic behavior, which is characteristic of a clustered structure, was observed above 451 K for all the alloy compositions.