Journal Article

Magnetic-field-induced shape recovery by reverse phase transformation

Oikawa, K., Imano, Y., Morito, H., Kitakami, O., Kainuma, R., Ito, W., Fujita, A., Ishida, K., Sutou, Y., Okamoto, S., Kanomata, T.

2006

Overview

Large magnetic-field-induced strains 1 have been observed in Heusler alloys with a body-centred cubic ordered structure and have been explained by the rearrangement of martensite structural variants due to an external magnetic field 1 , 2 , 3 . These materials have attracted considerable attention as potential magnetic actuator materials. Here we report the magnetic-field-induced shape recovery of a compressively deformed NiCoMnIn alloy. Stresses of over 100 MPa are generated in the material on the application of a magnetic field of 70 kOe; such stress levels are approximately 50 times larger than that generated in a previous ferromagnetic shape-memory alloy 4 . We observed 3 per cent deformation and almost full recovery of the original shape of the alloy. We attribute this deformation behaviour to a reverse transformation from the antiferromagnetic (or paramagnetic) martensitic to the ferromagnetic parent phase at 298 K in the Ni 45 Co 5 Mn 36.7 In 13.3 single crystal.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Alloys / Condensed matter: electronic structure, electrical, magnetic, and optical properties / Condensed matter: structure, mechanical and thermal properties / Cooling / Cross-disciplinary physics: materials science; rheology / Deformation / Deformation and plasticity (including yield, ductility, and superplasticity) / Exact sciences and technology / Heat treating / Humanities and Social Sciences / letter / Magnetic fields / Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.) / Magnetic properties and materials / Magnetically ordered materials: other intrinsic properties / Martensitic transformations / Materials science / Mechanical and acoustical properties of condensed matter / Mechanical properties of solids / multidisciplinary / Phase diagrams and microstructures developed by solidification and solid-solid phase transformations / Physics / Science / Science (multidisciplinary) / Temperature