Ferromagnetic shape memory effects in tetragonally distorted antiperovskite manganese nitrides

► Tetragonally distorted antiperovskite Mn3CuN is a different class of ferromagnetic shape memory alloy. ► Mn3CuN exhibits a large magnetostriction of up to 2000 ppm in the tetragonally distorted ferromagnetic phase, even in the polycrystalline form. ► The peculiarity of Mn3CuN as an FSMA is its small magnetocrystalline anisotropy, exemplified by rotation of the magnetic easy axis because of nitrogen deficiency. ► The operating magnetic field for magnetostriction is drastically reduced in the vicinity of the compositional region of easy-axis rotation, suggesting possible supermagnetostriction.