Phase transformation and magnetic properties of MnBi alloys by sintered and quenched

High-pure MnBi alloy was successfully synthesized by closed cryogenic sintering and then rapid quenching method. The phase transformation of the Mn-Bi samples in the sintering process were studied by differential thermal analyzer (DTA). The phases and magnetic properties of the samples were characterized by X-ray diffractometer (XRD) and vibration sample magnetometer (VSM). The results show that the low-temperature phase MnBi alloy block material with high purity can be obtained at 1:1.3 (n(Bi):n(Mn)), 275 ℃, 20 h. At 50~350 K, the magnetization decreases with the increasing of temperature, and the coercivity Hc and residual magnetization Mr decrease firstly and then increase. When the temperature is lower than 200 K, the sample is more likely to approach saturation with the decrease of temperature. At 50 K, the saturation magnetization of the sample is 78.0 Am2/kg. The preparation process used in this research is simple and the quantity production of alloy can be realized, which has an important reference value for the preparation of the new type alloy material. © 2021, Jilin University Press. All right reserved.