The Influence of Milling Modes on the Structure and Magnetic Properties of (Sm, Ho)₂Fe₁₇N_x (x = 0, 2.4) Powder Materials

The composition, structure, and surface topology of as-cast, homogenized, and nitrogenized alloy based on an intermetallic compound Sm₂Fe₁₇ with partial substitution of samarium atoms with holmium atoms have been studied using X-ray fluorescence and X-ray phase analysis, as well as scanning electron microscopy. Results on the magnetic properties of the initial compound Sm_1.2Ho_0.8Fe₁₇ and the nitride Sm_1.2Но_0.8Fe₁₇N_2.4 and its milled powders have been presented. It has been found that partial substitution of samarium atoms with holmium ones in a rare-earth metal sublattice in combination with the effect of introducing nitrogen atoms into the initial compound crystal lattice increases such magnetic characteristics as specific magnetization and coercive force. A comparative analysis of the magnetic hysteresis properties of powder samples showed that increasing the duration of the milling of the Sm–Ho–Fe–N powders using high-energy ball milling (15, 30, 45, and 60 min) contributes to improving the main magnetic characteristics. Functional characteristics obtained for Sm–Ho–Fe–N powders after their milling are important for the development of new high-coercivity magnets based on them.