Effect of Heat-Treatment on the Phases of Ni-Mn-Ga Magnetic Shape Memory Alloys
The Heusler alloys Ni50Mn25+xGa25-x display magnetic shape memory effect (MSM) with very fast and large reversible strain under magnetic fields. This large strain and the speed of reaction make MSM alloys attractive as smart materials. Our crystallographic investigation of these alloys, focused on non-stoichiometric composition with excess of manganese. Using neutron diffraction, we revealed the necessary processing parameters to achieve and preserve the homogeneous metastable one-phase martensitic structure that is needed for an MSM effect at room temperature.
P. Ari-Gur et al., "Effect of Heat-Treatment on the Phases of Ni-Mn-Ga Magnetic Shape Memory Alloys", Solid State Phenomena, Vols. 152-153, pp. 497-500, 2009