Influence of Er and Zr Content on the Phase Composition and Microstructure of SmCo Magnets with Low Remanence Temperature Coefficients

The influence of Er and Zr content on SmCo magnets with low remanence temperature coefficients is investigated. Variations of magnetic properties with Er and Zr content are analyzed. Results show that excessive Er substitution leads to phase separation, but the reduction of Zr content eliminates the impurity phases. First‐principle calculations reveal the stabilizing effect of Er on phases with Sm n +1 Co 5 n −1 structures. Magnets with satisfactory magnetic properties and temperature compensation are obtained, of which the one with 40% Er substitution exhibits (BH) max of 165 kJ·m − 3 at room temperature and a low‐temperature coefficient of remanence of −0.014%·°C −1 within the range of 20–100 °C.