The magnetic-field-dependence driving force for premartensitic transformation in Heusler alloy Ni2MnGa

Based on the electron–transverse acoustic (TA) phonon interaction model and by using the Wigner–Brillouin perturbation theory (WBPT), the effect of magnetic field on the driving force for the premartensitic transformation (PT) in the Heusler (L21) alloy Ni2MnGa has been investigated. The numerically calculated results reveal that the driving force of the PT increases with increasing external magnetic field owing to the interaction energy of the electron coupling with the phonon field and the magnetic field, and that low fields also influence the PT which is in agreement with the experimental observations.