Broadened linear remanence temperature compensation range of 2:17-Type SmCo magnets via tailored elemental distribution and phase composition

The rapid advancement in aerospace, defence and precision industrial instrumentation fields has intensified the demand for high-stability SmCo magnets with broad temperature compensation ranges. In this study, the linear remanence temperature compensation range in 2:17-type SmCo magnets was broadened through modulation of Dy content. The influence of Dy concentration on elemental distribution and phase composition was investigated. The results showed that increasing Dy content effectively expands the linear remanence temperature compensation range from 343-418 K ( ΔT = 75 K) to 263-523 K ( ΔT = 260 K), representing an extension of 246.7%. Dy preferentially distributed in the 2:17R phase and induced Cu enrichment at the lamellar/intracellular interface, simultaneously increasing the proportion of the 2:17R phase while decreasing the fraction of the 1:5H phase. Through the synergistic effects of element segregation and phase composition evolution, a low remanence temperature coefficient ( α ) of 0.00658 %/K and ( BH) max of 138.5 kJ·m -3 was achieved in the Sm 0.51 Gd 0.09 Dy 0.4 (Co 0.675 Fe 0.22 Cu 0.08 Zr 0.025 ) 7.4 magnet alongside the broadened temperature compensation range. These findings provide an important guidance for developing broad-temperature-range SmCo magnets with high remanence stability, advancing their application in broader range of fields.