The 2:17-type Sm-Co-Fe-Cu-Zr high-temperature magnets exhibit unique cellular nanostructure, with Zr-rich lamellar phase (Z-phase) penetrating through the 2:17R nanocells and 1:5H cell boundaries. In this work, a face-centered cubic (FCC) Zr-rich lamellar phase was identified in an Fe-rich Sm₂₅Co_42.9Fe_23.5Cu_5.6Zr_3.0 (wt.%) magnet. The orientation relationship between FCC and 2:17R phases is [100]-2:17 ∥ [1$\overline{1}$0]-FCC and (001)-2:17R ∥ (111)-FCC. Unlike the previously-reported hexagonal or rhombohedral Z-phases that are fully coherent with 2:17R or 1:5H phases, both the broad interphase (111)-FCC/(001)-2:17R and the (22$\overline{4}$)-FCC/(010)-2:17R interphase at the peripheries of the FCC Z-phase exhibit semi-coherent morphology, due to the large lattice mismatch. The semi-coherent FCC Z-phase can be attributed to the thickening of the coherent Z-phase that gradually loses coherency, as a result of a gradual reduction in elastic strain energy and interfacial energy. This finding may add new insights into the solid-state phase transitions of Sm-Co-based magnets.

2:17 型 Sm-Co-Fe-Cu-Zr 高温磁体具有独特的细胞纳米结构，富 Zr 层状相（Z 相）穿透 2:17R 纳米细胞和 1:5H 细胞边界。_{在这项工作中，在富含 Fe 的 Sm 25} Co _42.9 Fe _23.5 Cu _5.6 Zr _3.0 (wt.%) 磁体中鉴定出面心立方 (FCC) 富 Zr 层状相。FCC与2:17R相的取向关系为[100]-2:17∥[1$\overline{\mathrm{1个}}$0]-FCC 和 (001)-2:17R ∥ (111)-FCC。与先前报道的与 2:17R 或 1:5H 相完全相干的六方或菱形 Z 相不同，宽界面 (111)-FCC/(001)-2:17R 和 (22$\overline{\mathrm{4个}}$)-FCC/(010)-2:17R 界面在 FCC Z 相的外围表现出半相干形态，这是由于大的晶格失配。半相干 FCC Z 相可归因于相干 Z 相增厚，逐渐失去相干性，这是弹性应变能和界面能逐渐降低的结果。这一发现可能会为 Sm-Co 基磁体的固态相变增加新的见解。