Spark plasma sintered Sm<inf>2</inf>Co<inf>17</inf>-FeCo nanocomposite permanent magnets synthesized by high energy ball milling

Nanocomposite Sm2Co17-5 wt% FeCo magnets were synthesized by high energy ball milling followed by consolidation into bulk shape by the spark plasma sintering technique. The evolution of magnetic properties was systematically investigated in milled powders as well as in spark plasma sintered samples. A high energy product of 10.2 MGOe and the other magnetic properties of Ms = 107 emu g-1, Mr = 59 emu g-1, Mr/Ms = 0.55 and Hc = 6.4 kOe were achieved in a 5 h milled and spark plasma sintered Sm 2Co17-5 wt% FeCo nanocomposite magnet. The spark plasma sintering was carried out at 700°C for 5 min with a pressure of 70 MPa. The nanocomposite showed a higher Curie temperature of 955°C for the Sm 2Co17 phase in comparison to its bulk Curie temperature for the Sm2Co17 phase (920°C). This higher Curie temperature can improve the performance of the magnet at higher temperatures. © IOP Publishing Ltd.