Low-temperature superelasticity and elastocaloric effect in textured Ni–Mn–Ga–Cu shape memory alloys

Abstract The superelastic behavior and elastocaloric effect of a [001]-textured Ni50Mn23Ga25Cu2 polycrystal have been investigated below room temperature (256–294 K). The adiabatic temperature change caused by rapid unloading of uniaxial stress reached −4.3 K at 259 K. A small stress hysteresis of 14 MPa was observed. Due to the low hysteresis energy loss (0.37 MJ m−3) stemming from the texture structure, the coefficient of performance (COPmat) of our alloy was calculated to be 18, indicating that it is a promising elastocaloric candidate for low-temperature refrigeration.