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

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. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved