Magnetomechanical properties of a high-temperature Ni–Mn–Ga magnetic shape memory actuator material

A Ni–Mn–Ga single crystal with a phase transformation temperature above 350 K is investigated. The material demonstrates a magnetic field-induced strain (MFIS) of 7% at room temperature and of 4.2% at 350 K. The temperature dependence of the magnetic anisotropy and of the saturation magnetization has been studied in detail. At 350 K a maximum magnetic stress of 1.6 MPa and a twinning stress of 0.6 MPa were measured, explaining the MFIS obtained at elevated temperatures.