Enhanced magnetocaloric performance in nanocrystalline/amorphous Gd3Ni/Gd65Ni35 composite microwires

Abstract

A novel class of nanocrystalline/amorphous Gd3Ni/Gd65Ni35 composite microwires were created directly from melt-extraction through controlled solidification. X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) confirmed the formation of a biphase nanocrystalline/amorphous structure in these wires. Magnetic and magnetocaloric experiments indicate a large magnetic entropy change (-Delta S-M similar to 9.64 J/kg K), large refrigerant capacity (RC similar to 742.1 J/kg), and large maximum adiabatic temperature change (Delta T-ad(max)-5 K) around the Curie temperature of similar to 120 K for a field change of 5 T. These values are similar to 1.5 times larger relative to its bulk counterpart and are superior to other candidate materials being considered for active magnetic refrigeration in the liquid nitrogen temperature range. (C) 2021 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi.