Effects of Annealing Temperature and Magnetic Field on the $\varepsilon\hbox{--}\tau$ Phase Transformation in Mn-Al Alloys

Magnetic field effects on the transformation from the hexagonal close-packed ε-phase to the ferromagnetic L1
₀
τ-phase were evaluated for Mn-Al alloys annealed at 573, 623 and 673 K in magnetic fields up to 15 T. The phase transformation from the ε-phase to the τ-phase was enhanced by the magnetic field for the 623 K annealing temperature. These in-field annealing effects are explained by the Zeeman energy of the ferromagnetic τ-phase.