- Gao, TR;
- Fang, L;
- Fackler, S;
- Maruyama, S;
- Zhang, XH;
- Wang, LL;
- Rana, T;
- Manchanda, P;
- Kashyap, A;
- Janicka, K;
- Wysocki, AL;
- N’Diaye, AT;
- Arenholz, E;
- Borchers, JA;
- Kirby, BJ;
- Maranville, BB;
- Sun, KW;
- Kramer, MJ;
- Antropov, VP;
- Johnson, DD;
- Skomski, R;
- Cui, J;
- Takeuchi, I
We demonstrate substantial enhancement in the energy product of MnBi-based magnets by forming robust ferromagnetic exchange coupling between a MnBi layer and a thin CoFe layer in a unique perpendicular coupling configuration, which provides increased resistance to magnetization reversal. The measured nominal energy product of 172kJ/m3 at room temperature is the largest value experimentally attained for permanent magnets free of expensive raw materials. Our finding shows that exchange-coupled MnBi/CoFe magnets are a viable option for pursuing rare-earth-free magnets with energy products approaching those containing rare-earth elements.