Investigation of low field response of metamagnetic Heusler alloys as multiphysic memory alloys

Extending the concept of shape memory alloys, multiphysic memory alloys (MPMAs) based on Heusler compounds show remarkable properties in terms of multiphysic transitions coupling thermal, structural and magnetic domains. Such characteristics thus unveil new application potentials in the field of actuation or energy harvesting for instance. In particular, one of the most notable features of such materials lies in the presence of a magnetic response in a particular temperature range. In order to further investigate the origin of such characteristics, this study aims at providing qualitative and quantitative theoretical insights for shaping potential future material developments and tailoring, along with experimental investigations supporting the proposed theoretical framework. Such a development is done by considering that the unique MPMA behavior originates from the combination of a first-order hysteretic structural transition between martensitic and austenite phases with a ferromagnetic behavior of the austenite phase. Comparison of such an approach with experimental magnetic property measurements of a metamagnetic Heusler nickel-cobalt-manganese-indium alloy shows a good ability to predict the low-field magnetic response, highlighting the main involved parameters for further developments.