High-performance resin-bonded magnets produced from zinc metal-coated Sm2(Fe0.9Co0.1)17Nx fine powders

Fine powders of Sm2(Fe0.9Co0.1)17Nx (x=∼3) with particle sizes (d) around 1 μm as coated with zinc metal produced via the photodecomposition of diethylzinc [Zn(C2H5)2], which still provided high remanence (Br) and coercivity (Hcj) values of ∼1.43 T and ∼0.85 MAm−1, were molded to compression-type resin bonded Zn/Sm2(Fe0.9Co0.1)17Nx magnets with density values of ∼6.33 g cm−3. By optimizing the preparation conditions such as grinding, surface coating, and molding for them, the highest maximum energy product of (BH)max=186 kJm−3 for Hcj=0.73 MAm−1 was recorded among all kinds of the Sm–Fe–N based magnets reported to date. Furthermore, the excellent aging behavior of the bonded Zn/Sm2(Fe0.9Co0.1)17Nx magnets was observed after standing in air at ∼393 K and the thermal coefficient for permanent magnet was evaluated to be α(Br)=−0.04% K−1.