Phase modification and magnetic energy product enhancement of PrCo5-based nanomaterials due to carbon addition.

The magnetic properties, phase evolution, microstructure, and magnetic domain structure of melt-spun PrCo 5- x C x and PrCo 5 C y (x = 0–0.4 and y = 0–0.4) flakes are compared. Binary PrCo 5 flakes exhibit low intrinsic coercivity (i H c) of 3.2 kOe and thus a low magnetic energy product ((BH) max) of 4.4 MGOe, which is attributed to the coarse grains. By doping with proper amounts of C, the well-modified phase composition and uniformly refined microstructure and magnetic domains enhance the magnetic properties remarkably. Different phase compositions found for two approaches for doping PrCo 5 with C dominate the magnetic properties in addition to the fine microstructure. In PrCo 5- x C x (x = 0–0.4) flakes, the 2:17 phase suppressed by doping with C contributes to coercivity increase, and the largest i H c of 13.5 kOe with (BH) max = 8.8 MGOe is obtained for PrCo 4.9 C 0.1 flakes. For higher x , the formation of the 5:19 phase slightly reduces i H c to 7.2–8.8 kOe and (BH) max to 7.2–8.0 MGOe. In contrast, in the PrCo 5 C y (y = 0–0.4) series flakes, the increased amount of the 2:17 phase and the strengthened exchange coupling effect resulting from the refined microstructure caused by doping with a proper amount of C result in large (BH) max of 11.8 MGOe with i H c of 5.0 kOe for PrCo 5 C 0.3 flakes. • C doping significantly improves the magnetic properties of melt-spun PrCo 5 flakes. • C doping refines the sizes of the grains and magnetic domains. • Different phase compositions for two approaches for C doping dominate the magnetic properties. • In PrCo 5- x C x , the suppressed 2:17 phase resulting from doping with C contributes to high intrinsic coercivity. • In PrCo 5 C y flakes, the 2:17 phase well coupled with the 1:5 phase results in high (BH) max. [ABSTRACT FROM AUTHOR]