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

在300- 773 K温度范围内，在高达45 T的磁场中，对铁磁材料MnBi进行了差热分析。当外加磁场为45 T时，MnBi -> Mn 1.08Bi+液相的分解温度Tt由零场时的632 K提高到714 K。此外，还得到了18 T下的Bi-Mn相图，该相图与零磁场下的相图有很大的不同。同时还得到了18 T以上强磁场下的Fe-C钢相图。用相图计算机耦合（CALPHAD）方法对强磁场下Bi-Mn二元相图进行了热力学计算。计算结果表明，磁场作用下Bi-Mn相图发生了明显的变化，这与本课题组进行的现场热分析实验结果吻合较好。

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.