The magnetically driven shape memory effect in Ni2MnGa body-centered tetragonal martensite was onset by the motion of 0.144 <111> type twin dislocations on the {112} type planes. Calculations show that the application of a 400kA/m magnetic field could induce a shear stress of approximately 2.8MPa on these twin dislocations, a value exceeding the Peierls and the yield stress for Ni2MnGa.

A Dislocation Model for the Magnetic Field Induced Shape Memory Effect in Ni2MnGa. S.Rajasekhara, P.J.Ferreira: Scripta Materialia, 2005, 53[7], 817-22