Experimental Study on the Magnetomechanical Characteristics of Ni-Mn-Ga Ferromagnetic Shape Memory Alloy Single Crystals

Magnetic shape memory properties of Ni-Mn-Ga single crystals were characterized by measurement of stress-induced martensite reorientation under constant magnetic fields. Also magnetic field-induced strain as a function of the applied magnetic field under different constant compressive stress levels has been investigated. All the experiments were performed at room temperature in which the sample is in its martensite phase. Compressive stress and magnetic field were applied perpendicular to each other, and strain was measured along the compressive load axis. Magnetoelasticity, martensite reorientation, shape memory effect, and pseudoelasticity were observed throughout the experiments. Moreover, twinning stress and blocking stress were obtained.