Ferromagnetic Shape Memory Alloys—Challenges, Applications, and Experimental Characterization

Ferromagnetic shape memory alloys (FSMA) constitute a subgroup of shape memory alloys (SMA) that also exhibit a ferromagnetic behavior. Due to the unique combination of large displacements and fast mechanical response, FSMA offer prospects for novel applications that make use of new mechanism for converting between magnetic and mechanical energies. This review article provides basic tools for understanding and characterizing FSMA and explores their potential use as actuating materials. In particular, we describe the unique deformation mechanisms of FSMA and the key properties and characteristics that govern these deformation mechanisms, as well as the main experimental methods for characterizing these properties. In addition, the article discusses potential actuation and energy-harvesting applications for FSMA and the up-to-date challenges in integrating FSMA devices in commercial applications.