Dislocation motion in antiferromagnetic γ-FeMn alloys

The plastic deformation of γ-FeMn alloys has been investigated by tensile and stress relaxation tests and transmission electron microscopy. The flow stress increases below the Néel temperature and reaches about 1 kp/mm2 at room temperature, but the activation volume and dislocation configuration do not change. This may be understood by the magnetic friction for dislocation motion in antiferromagnetic γ-FeMn alloys, which is associated with the newly-produced ferromagnetic coupling at the nearest neighbour site rather than a change of the deformation process.