Tailoring Magnetic Properties to Improve Energy Product in Mn‐Substituted SmCo 5 Prepared Using Mechanical Milling

SmCo 5 magnets play a vital role in permanent magnets due to their unique combination of high magnetic strength, excellent thermal stability, and durability. Here, we investigate the influence of milling time ( t mill ) and composition on structural and magnetic properties of SmCo 5− x Mn x ( x = 0–0.15) powders, synthesized via arc melting followed by controlled ball milling. Structural analysis reveals that Mn preferentially substitutes for Co, leading to unit cell volume expansion. The increase in t mill and x results in progressive refinement of crystallites and promotes the formation of strained nanocrystalline powders with average microstrain and dislocation density of 10 −4 –10 −3 and 10 −3 –10 −2 nm −2 . Magnetization at 90 kOe ( M 90kOe ) increases monotonically with x , reaching 13% enhancement at x = 0.15. In contrast, coercivity ( H C ) first increases to 11.2 kOe at x = 0.05, and then decreases. The optimal magnetic performance is achieved at x = 0.05, where simultaneous enhancements in both H C and M 90kOe yield a maximum energy product of 5.12 MGOe, representing ~3% improvement. Analysis of initial magnetization curves, differential susceptibility, and irreversible magnetization indicates that magnetization reversal is governed by a pinning‐dominated mechanism. These results demonstrate a viable approach to tailoring and improving the hard‐magnetic properties of SmCo 5 , thereby enhancing its potential for advanced permanent magnet applications.