| Abstract Scope |
Ni-Mn-based magnetic shape memory alloys (MSMAs) are active materials that undergo martensitic transformations induced by temperature, stress and/or magnetic fields, leading to large recoverable mechanical transformations. As a result of the strong magnetoelastic coupling they show, these alloys can present large magnetostrains, due to either a reorientation of martensitic twin-variants or a magnetic-field induced martensitic transformation.
NiMnGaCo-based alloys present a metamagnetic behaviour in their martensite phase, where stoichiometry controls the critical temperatures: structural, Tm, and magnetic, Tc. It is well assessed that the cyclability of the magnetostriction depends on the hysteretic character (sharpness and temperature) of the structural transformation. In this work, Ni-Co-Mn-Ga-In alloys were doped with Fe to analyse its effect on the hysteresis of the martensitic transformation (MT). Trends in the MT, Curie temperatures, as well as in the magnetization change across the MT, will be discussed in a series of Ni-Mn-Ga-Co-In-Fe (%At Fe = 0-5) meta-MSMAs. |