Development of Cu-Mn-Ga-based ferromagnetic shape memory single crystals

In this study, for the first time, the Cu-Mn-Ga-based ferromagnetic shape memory single crystals are produced only through annealing their cast polycrystalline alloys, and their functional properties are reported. The abnormal grain growth during annealing attributes to the unique microstructure with the body-centered cubic nanoparticles uniformly distributing within the Heusler L21 (Cu2MnGa) parent. Finally, the single crystals over cm-scale are produced, and they show a large stress platform indicating potential excellent shape memory effect, or up to 3% of superelastic strain. The obtained results should be of great significance for the development of brittle Cu-Mn-Ga ferromagnetic shape memory alloys.