Effect of temperature on magnetic field-induced response of Ni-Mn-Ga single crystals

This study presents an experimental and theoretical investigation into the effect of temperature on the magnetic field-induced responses of Ni-Mn-Ga single crystals, such as reorientation behaviour, critical threshold fields and hysteresis loops. Nano-indentation, differential scanning calorimetry and magnetic field-induced strain tests were conducted. The experimental results reveal that the critical threshold field decreases with an increase in temperature under a constant compressive stress. A revised magnetization rotation angle equation was developed by considering the effect of temperature on material magnetic anisotropy. By comparing with the measured magnetic field-induced strain versus magnetic field curves, the present theoretical model is shown to be capable of predicting the effect of temperature on the macroscopic responses of magnetic shape memory alloy.