低酸素化によるSm-Fe-N系バルク磁石の高特性化

The magnetic properties of Sm-Fe-N based bulk magnets were improved using powders with low-oxygen content, and high coercivity Zn-bonded Sm-Fe-N magnets and high (BH)max Sm-Fe-N magnets were successfully obtained. The fine Zn powder with low-oxygen content was prepared by the Hydrogen-Plasma-Metal-Reaction (HPMR) method. The oxygen content was only 0.068 wt% (680 ppm), and the oxygen content of Zn-bonded Sm-Fe-N magnets preparing from HPMR-Zn powder also decreased. 15 wt% Zn-bonded Sm-Fe-N magnet showed high coercivity of 2.66 MA・m-1, and 10 wt% Zn-bonded magnet also showed high coercivity of 2.41 MA・m-1. In this study, low-oxygen content Sm-Fe-N powder was also prepared. The low-oxygen content Sm-Fe-N powder was sintered by Spark-Plasma-Sintering (SPS), and the Sm-Fe-N bulk magnet showed high maximum energy products of 179 kJ・m-3.

This work was partially supported by the Future Pioneering Program“Development of magnetic material technology for high-efficiency motors” commissioned by the NewEnergy and Industrial Technology Development Organization (NEDO), the Elements Strategy InitiativeCenter for Magnetic Materials (ESICMM) under the outsourcing project of MEXT and Japan Societyfor the Promotion of Science (JSPS) KAKENHI Grant Number 16K144310.