Thermodynamic assessment for the Bi-Mn binary phase diagram in high magnetic fields

摘要

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 magnetic total energy E_(mag) was estimated by calculating magnetization on the basis of the mean field theory. 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 Mitsui et al. The calculation shows that the peritectic temperature T_(p1)(BiMn + liquid -> BiMn_(1.08) + liquid) reached another peritectic temperature T_(p2) (BiMn_(1.08) + liquid -→ Mn + liquid) at 49 T, suggesting that BiMn will form directly from Mn + liquid without forming BiMn_(1.08) by the heat treatment in B ≥ 49 T.