It was recalled that twinning stresses or mechanical hysteresis associated with twin boundary motion was one of the most essential parameters which determined the actuating performance of magnetic shape memory alloys. Recent efforts aimed at decreasing the twinning stress resulted in a consistent production of Ni-Mn-Ga magnetic shape memory single crystals with the twinning stress of about 0.1MPa, which was much lower than previously reported. The mechanical and magnetomechanical response of the developed crystals was considered in detail and the importance of adjusting the twin microstructure in order to obtain the optimal actuating behavior was illustrated.

Ni-Mn-Ga Single Crystals with Very Low Twinning Stress. L.Straka, H.Hänninen, A.Soroka, A.Sozinov: Journal of Physics - Conference Series, 2011, 303[1], 012079