Martensitic twins and antiferromagnetic domains in γ-MnFe(Cu) alloy

The multi-function characteristics of Mn-base alloys are related to the domains accompanying the antiferromagnetic transition and twins resulting from the fcc–fct martensitic transformation. The morphology and orientation of the twins have been investigated with transmission electron microscopy. Fringe pattern which result from twin boundaries were observed, and they are found to be {0 1 1} type as indicated by electron diffraction. It is proved with Landau theory that the fct twin corresponds to one kind of antiferromagnetic domain as the martensitic transformation is induced by antiferromagnetic ordering.