Investigation of the effect of high magnetic field on the MnBi/Mn1.08Bi phase transformation in Mn-Bi alloys by measuring the magnetic force in gradient magnetic field

Owing to the change in magnetic susceptibility while the phase transformation occurs, a new method is suggested to determine the phase transformation temperature by measuring the temperature at which the magnetic force changes abruptly in a gradient magnetic field. The MnBi/Mn1.08Bi phase transformation temperature in a high magnetic field is measured by this method and the result indicates that the magnetic field has increased the phase transformation temperature; as a result, a 10 T field increases the phase transformation temperature about 20 °C. The microstructures of the primary phase around the phase transformation without and with the magnetic field have been investigated, and the change of the phase morphology agrees well with the phase transformation determined by the above method.