MnBi-Based Bulk Magnets: Preparation and Magnetic Performance

High-performance bulk magnets based on MnBi alloys have been attractive to researchers globally since the early 1950s. Recently, there has been renewed interest into these types of magnets because of their high performance at high working temperatures and the absence of rare earth elements. In comparison with rare-earth-containing magnets, the disadvantage of this material is the low intrinsic spontaneous magnetization (~ 8.2 kG) and the lower value of saturation magnetization of green powders used for making bulk magnets. So, both magnetization and coercivity become extrinsic and their values depend on the techniques used in their preparation. The paper analyses the technological steps of making high-performance magnets and emphasizes the challenges in developing single-phase MnBi and nanocomposite MnBi/Co-nanowire magnets.