It was recalled that magnetic shape-memory materials combined ferro-elastic and ferromagnetic order. The diffusionless transformation processes in these materials proceeded via the creation of crystallographic domains or twinned microstructures that were coupled to magnetic domain patterns. Miniaturization of the crystallographic domains to the scale of lattice unit cells was possible via the concept of adaptive modulated martensite. A ferro-elastic model for these crystallographic domain patterns was introduced for the case of the Ni2MnGa Heusler alloy. The pseudo-microscopic model incorporated data from ab initio calculations and phonon dispersion. The twin-boundary energy for the diffuse wall of this model was of the order of 1mJ/m2.

Domain Models of Ferromagnetic Shape Memory Materials. U.K.Röássler: Advanced Engineering Materials, 2012, 14[8], 589-93