Damping mechanism associated with coupling between antiferromagnetic transition and martensitic transformation

Abstract

To study the relationship between the martensitic transformation and the antiferromagnetic transition and to develop new twin-based high damping materials, the internal friction and modulus in γ Mn-based Mn–Fe and Mn–Ni alloys were measured. Three internal friction peaks were observed between −100 and 400 °C, namely at the Néel temperature T N, the martensitic transformation temperature M S and 0 °C. They are related to the antiferromagnetic transition, the martensitic transformation and twins in the fct phase. The first is accompanyied by a rapid decreases of modulus at T N. The third, high damping peak is similar to the one observed in Mn–Cu alloys, and is attributed to the fcc–fct martensitic transformation or to fine twins in the antiferromagnetic domains.