Giant reversible stress-induced change of resistivity in Ni-Mn-In-Co alloys

Abstract

Ni43Mn37.8In12.2Co7 and Ni43Mn37.65In12.35Co7 polycrystalline alloys were tested mechanically in uniaxial compression in order to determine the stress-strain response and accompanying changes of electrical resistivity. Compression of the specimen by 9% at room temperature resulted in a 250% increase of resistivity followed by almost full recovery to its predeformation level upon heating to 400 K. Microstructural observations revealed that giant reversible changes of electrical resistivity occurred due to stress-induced martensitic transformation and shape recovery of plastically deformed grains induced by heating.