Manufacture and characterization of RE2Co (RE=Gd, Ho) amorphous alloys with excellent magnetic entropy change

The structure, low -temperature magnetic transition behaviors, and magnetocaloric properties of rare -earth -based binary RE2Co (RE = Gd, Ho) amorphous alloys were studied. With the increase of temperature, the amorphous alloys undergo a phase transition from the ferromagnetic state to the paramagnetic state. In the paramagnetic region, the reciprocal magnetic susceptibilities of Gd2Co obey the Curie -Weiss law. The effective magnetic moment value was determined to be 13.4 mu B/f.u., with the corresponding paramagnetic Curie temperature of 187 K. The maximum values of magnetic entropy changes for RE2Co (RE = Gd, Ho) are achieved to be 9.9 J/kg K (3.7 J/mol K) and 14.7 J/kg K (5.7 J/mol K), respectively, for a field change of 0-5 T. Benefiting from the relatively wide operating temperature range, large refrigerant capacity values were obtained, being 636.4 J/kg and 479.5 J/kg for Gd2Co and Ho2Co, respectively (0-5 T). This study underscores the potential of RE2Co (RE = Gd, Ho) amorphous alloys as promising magnetocaloric materials for cryogenic applications.