Atomistic Insights Into Site Preference of Dopants and Its Impact on Magnetic Moment in SmFe 12 ‐Based Magnets

Element doping stabilizes SmFe 12 ‐based magnets but typically reduces saturation magnetization. To elucidate the underlying mechanisms, this study employs first‐principles calculations to analyze the site preference of eight dopants (Ti, V, Ga, Al, Si, Nb, Mo, Co). Results indicate that Ti, V, Nb, and Mo prefer the 8 i site, while Al, Ga, and Si occupy the 8 j site. The total magnetic moment is primarily determined by three factors: (1) Site‐specific Fe moments, following the order μ (8 f ) <  μ (8 j ) <  μ (8 i ), where 8 i ‐substitution causes the largest moment loss; (2) the intrinsic magnetism of doping elements, which, based on density of states (DOS) analysis, are classified into a negative contribution group with moments anti‐parallel to Fe (Ti, V, Nb, Mo), a non‐magnetic group (Al, Ga, Si), and a positive contribution group (Co); and (3) the influence of doping elements on surrounding Fe moments, where Co, Ga, and Al significantly enhance the total magnetic moment of surrounding non‐substituted Fe atoms. This work provides a quantitative framework for screening magnet candidates specifically from the perspective of optimizing saturation magnetization and site‐occupation trends.