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

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 Delta V/V (-1.24%), the large entropy change Delta S-tr 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.