Large room-temperature elastocaloric effect and enhanced specific adiabatic temperature change of Ni–Mn-based shape memory microwire

Abstract

Continuous miniaturization of electronic components puts higher demands on the heat dissipation of the micro-systems, which requires environmental friendliness, good heat exchange capability, and high-performance micro-refrigeration materials. Here, we developed a Ni–Mn–Fe–In microwire fabricated by the Taylor–Ulitovsky method, showing ⟨001⟩A orientation close to the axial direction of microwire. Due to the large volume change ΔV/V (−1.24%), the large entropy change ΔStr of 43.6 J kg−1 K−1 was achieved in the microwire. Owing to the low driving force of the microwire with a single crystalline of ⟨001⟩A orientation close to the axial direction of microwire, large adiabatic temperature change of −5.7 K was achieved at room temperature after removing a low stress of 120 MPa. Thus, high specific adiabatic temperature change of 47.5 K/GPa was obtained in the microwire, which is the highest value among all the reported low-dimension elastocaloric materials, including thin films/foils, microwires/wires, and ribbons. The outstanding comprehensive properties give this microwire a great application potential in miniaturization and compactness of refrigeration devices.