The study on phase diagram of magnetic materials and alloys under high magnetic fields for development of new functional materials

对温度为300-773K的铁磁材料MnBi在45 T磁场下进行了差热分析，在45 T磁场作用下，分解温度Tt （MnBi -> Mn1.08 Bi +液相）从632 K（零场）增加到714 K，得到了18 T时的Bi- mn相图，与零磁场下的相图有很大不同。我们还得到了在超过18 t的强磁场下Fe-C钢的相图，并利用相图计算机耦合（CALPHAD）方法进行了高磁场下Bi-Mn二元相图的热力学计算。计算结果表明，在磁场作用下，Bi-Mn相图发生了明显的变化，这与课题组现场热分析的实验结果吻合较好。

Differential thermal analysis was carried out for ferromagnetic material MnBi in the temperature range 300-773K in magnetic fields up to 45 T. The decomposition temperature Tt (MnBi -> Mn1.08 Bi + liquid) increases from 632 K (at a zero field) to 714 K by applying a magnetic field of 45 T. In addition, the Bi-Mn phase diagram at 18 T was obtained, which quite different from that at a zero magnetic field. We also obtained the Fe-C steel phase diagram under high magnetic fields over 18 T. The thermodynamic calculations of the Bi-Mn binary phase diagram in high magnetic fields are carried out by the Computer Coupling of Phase Diagrams (CALPHAD) method. The calculated results show the significant change of the Bi-Mn phase diagram under magnetic fields, which were in good agreement with the experimental results of in-field thermal analysis performed by our research group.