The thermal stability and microwave electromagnetic properties of MnN.

Microsized MnN powders have been prepared via a convenient route by the reaction of pure electrolytic manganese powder and ammonia in a tube furnace at 900 °C. The microstructure, morphology, thermal stability, magnetism as well as electromagnetic properties were characterized by powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, vibrating sample magnetometer and vector network analyzer. The enhanced relative complex permeability, complex permittivity and static magnetic were achieved when compared with pure manganese. Moreover, MnN had good thermal stability and oxidation resistance below 300 °C in air. A possible mechanism of the improved properties of MnN was discussed based on first-principles calculations. The results revealed that MnN could be a potential microwave absorbent. [ABSTRACT FROM AUTHOR]