Large magnetic-field-induced strain in Co-Ni-Al single-variant ferromagnetic shape memory alloy

At room temperature, Co41Ni32Al27 single-variant ferromagnetic shape memory alloy with a uniaxial magnetic anisotropy constant of -2.0 × 106 erg cm-3 exhibits a large magnetic-field-induced strain of 3.3% under a static compressive stress of about 10 MPa applied along the hard magnetization direction of the c-axis (c/a > 1). Compared with data for other alloys, it becomes clear that a small change in twinning stress in the stress-strain curve is necessary for a large strain.