2020年2月8日，以一年级博士生袁涛为第一作者的论文“Role of primary Zr-rich particles on microstructure and magnetic properties of 2:17-type Sm-Co-Fe-Cu-Zr permanent magnets”被 Journal of Materials Science & Technology（JMST）录用。祝贺袁涛！

这是课题组在Sm-Co高温永磁材料领域的第2篇论文，主要发现Sm-Co-Fe-Cu-Zr磁体中的富Zr初生析出相对时效过程中的扩散型相变有重要影响，从而对时效后的显微组织和磁体的磁性能有不利作用，应予以消除。论文从磁性能、微结构表征、构效关系、形成机制和抑制方法等方面进行了系统讨论。据悉，JMST是目前为数不多的被收入中科院一区刊物目录的国内杂志之一，其稿件录用率仅为7%。

附论文摘要：

Trace Zr addition is essential for achieving desired cellular nanostructure and large coercivity in the pinning-controlled 2:17-type Sm-Co-Fe-Cu-Zr magnets that have served as the strongest high temperature permanent magnets for over 40 years. However, accompanying this is the formation of Zr-rich particles that may deteriorate the hard magnetic properties.Besides the formerly-reported 1:3R Zr-rich platelets, in this work, 1~2 micron sized Zr₆(Co, Fe)₂₃ (6:23) particles (Fm-3m) and 100~200 nm sized 1:3R Zr-rich particles are also found based on combined structural identifications and element mapping analysis. Around such particles, the desired 1:5H cell wall precipitates that provide the strongest pinning force of magnetic domain wall motions are rare, forming the precipitate-free-zones (PFZs). The 1:5H-PFZs and the soft magnetism of both 6:23 and 1:3R Zr-rich particles act as local weak pinning points, which are unfavorable to retain the large magnetization in strong opposite fields and lead to poor squareness. As observed in a Sm₂₅Co_45.9Fe_19.5Cu_5.6Zr_4.0 (wt.%) magnet, the co-existence of such Zr-rich particles and the associated 1:5H-PFZs leads to a pretty low squareness factor of only 52.89% given the large coercivity of 29.04 kOe. Our findings suggest that careful controlling the Zr content and avoiding its aggregation to form harmful 6:23 and 1:3R Zr-rich particles are essential for achieving high squareness as well as large energy product in the Sm-Co-Fe-Cu-Zr permanent magnets.