HDDR法を用いたSm₂Fe₁₇N_x+Fe複合磁石の作製

抄録

Preparation and magnetic properties of Sm₂Fe₁₇N_xα-Fe composite magnets obtained by HDDR method have been investigated. Sm-Fe alloys prepared by arc melting were rapidly quenched at a surface velocity of V_s=50 m/s. These as-quenched ribbons, containing 6∼8 at%Sm, possessed a Sm-Fe phase of TbCu₇-type. After HDDR treatment, a Th₂Zn₁₇-type Sm-Fe phase and an α-Fe phase were observed. Sm₂Fe₁₇N_x+α-Fe composite magnets were obtained by subsequent nitrogenation.
Nitrogenated Sm₈Zr₂Fe₉₀ powders exhibited high magnetic properties with σ_m=115 emu/g and H_cJ=12.4 kOe, after applying magnetization field of 50 kOe. These powders showed σ_r/σ_m ratio of 0.63 without demagnetization correction.