Effect of Nb and C additives on the microstructures and magnetic properties of rapidly solidified Sm–Co alloys

Phase transformation, grain refinement and magnetic properties in melt-spun SmCo7−x(Cr3C2)x (x=0–0.25) ribbons

“…On the other hand, finer grains (20-50 nm) are also requisite for the increase in magnetic properties [12]. A small amount of carbon addition has been reported to be quite helpful for the grain refinement in the system of Sm-Co-Hf-C [13], Sm-Co-Nb-C [14], and Sm-Co-Fe-Mn-C [15]. It is reported that the grain size of C-doped SmCo 7 ribbons significantly decreases from a few hundred nanometers to below 50-90 nm [13,15].…”

Microstructural selection in conventionally and rapidly solidified Sm–Co–T alloys

“…An extra 5 wt.% Sm was added to account for vaporization losses during melting. Note that the binary eutectic between Co and Sm2Co17 occurs at approximately 8 at.% Sm (x = 0.08 and y = 0 in the above equation) [12]. Samples were re-melted to ensure homogeneity.…”

“…has been observed, insufficient magnetic hardening resulted in low coercivity [11]. Ternary (and above) alloying elements have effectively refined the scale of the structure in Sm-Co-based alloys produced by melt spinning, resulting in high coercivity [5,6,12]. However, the ternary alloying elements may significantly influence both the stability of the eutectic growth front and phase selection upon solidification.…”

Effect of Exchange Interactions on the Coercivity of SmCo5 Nanoparticles Made by Cluster Beam Deposition

“…However, it has been realized that that the coercivity improvement is due to the grain refinement in low C regime and grain boundary phase formation (Sm2C3) in high C regime which insulates the grains from each other. [38] Furthermore, ternary phase studies of the Sm-Co-C showed that C is not soluble in SmCo5 even at 900°C. [39] Consequently, in our samples, C just acts as a separator between the particles to reduce the exchange interactions.…”