Field-Controlled Shape Memory Effect and Temperature Stability of the Magnetic-Field-Induced Strain in Ni52Mn16.4Fe8Ga23.6 Single Crystal

Abstract:

Ferromagnetic Ni-Mn-Fe-Ga single crystal of a pseudoquaternary Heusler alloy has been invested as a new magnetic field control actuator material. A single crystal of Ni52Mn16.4Fe8Ga23.6 was grown in [001] direction of the cubic parent phase by the Czochralski method. The field-controlled shape memory effect and the temperature dependent of the magnetic-field-induced strain (MFIS) in Ni52Mn16.4Fe8Ga23.6 single crystal were investigated by measuring the field enhanced transformation strain and the MFIS with a magnetic field applied in different directions. The results show that such material combined with the martensitic transformation can produce the large field-enhanced transformation strain and the large MFIS. It is found that the MFIS is almost temperature independent, the maximum decreasing magnitude of the saturated MFIS is less than 10% from 265 K to 100 K. In addition, the direction in which the MFIS has the largest value is always the [001], namely the growth direction of the crystals. The results are discussed with reference to the shape memory characteristics of the alloys and the mechanism of the preferentially orientation of martensitic variants.

Key words:shape memory effect,magnetic-field-induced strain,martensitic shape transformation,temperature stability