Effect of Zr, V, Nb, Mo, and Ta substitutions on magnetic properties and microstructure of melt-spun SmCo5 magnets

We have investigated effects of metal substitutions on the magnetic properties and microstructure of melt-spun Sm-Co-Cu-Fe-M (M = Zr, V, Nb, Mo, Ta) magnets. We prepared melt-spun ribbons with compositions of Sm(Co1−xCux)5Fe0.54−yMy (x = 0.1–0.5, y = 0–0.43, M = Zr, V, Nb, Mo, Ta). For compositions of Sm(Co1−xCux)5Fe0.54 (x = 0.1–0.5), coercivity increased with increasing of annealing temperature, and a high coercivity of 17.6 kOe was obtained at a Cu content of x = 0.3. The coercivity was found to increase with increasing melting point of the substitution element. A high coercivity of 24.5 kOe was obtained for a composition of Sm(Co0.7Cu0.3)5Fe0.34Ta0.2.