2020年2月18日，课题组博士生周相龙为第一作者的论文“Identifications of SmCo₅ and Sm_n+1Co_5n-1-type phases in 2:17-type Sm-Co-Fe-Cu-Zr permanent magnets” 被Scripta Materialia录用。祝贺！

2:17型Sm-Co-Fe-Cu-Zr磁体是目前磁性最强的高温永磁材料，最高使用温度可达550℃，是航天飞行器姿态控制系统和新一代高铁大功率牵引系统的首选。该材料的硬磁性源于经烧结、固溶、时效和慢冷处理后所形成的纳米胞状组织，即胞内的2:17R菱方相、胞壁的1:5H六角相和贯穿胞状组织的1:3R富Zr片层相。1:5H相各向异性最强，可钉扎磁畴壁移动，对矫顽力起关键作用。然而，关于1:5H薄壁相的形成过程长期存在争议：有学者认为它在800~850℃时效过程中已经形成；也有学者认为先形成Sm_n+1Co_5n-1型中间相，在慢冷至400℃后才形成最终的1:5H相。本文的工作表明：在Fe含量较高的固溶处理态样品中已经形成了1:5H相，表明它是早期脱溶析出的产物。另外，在晶界附近也观察到了富Zr的Sm_n+1Co_5n-1相，它们作为初生析出相影响后续1:5H析出相的分布，造成晶界附近少于晶内，是晶界优先退磁的结构根源。

论文摘要：

Both SmCo5 and Sm_n+1Co_5n-1-type phases were identified in the Sm₂₅Co_42.9Fe_23.5Cu_5.6Zr_3.0 (wt.%) commercial sintered magnet even at the solution-treated state, with the 1:5H cell boundary phase occupying pyramidal planes, the 1:3R (n=2) thin platelets occupying the basal planes, and the mixture of 1:3R, 2:7R (n=3) and 5:19R (n=4) phases distributing at grain boundaries. The mixed Sm_n+1Co_5n-1-type phases at grain boundaries act as primary sinks and lead to sparse 1:5H-precipitates surrounding them after isothermal aging. It clearly reveals that the 1:5H cell boundaries are formed at the early decomposition stage and why they are rare at grain boundaries in the aged magnets.