Magnetic and magnetocaloric properties of GdNi (x) Al2-x (0.35 a parts per thousand currency sign x a parts per thousand currency sign 0.70) alloys with multiphase structure

摘要

The multiphase GdNi (x) Al2-x (0.35 a parts per thousand currency sign x a parts per thousand currency sign 0.70) compounds were synthesized, and the relationship between the composition and magnetic and magnetocaloric properties of the as-cast alloys was subsequently established in this work. For the alloys with composition close to the GdNiAl-end, large magnetic entropy changes occur. Decreasing ratio of Ni to Al induces considerable refrigerant capacity due to the large broadening of temperature range of the phase transitions. In particular, a plateau-shaped magnetocaloric feature was found in the fully crystalline GdNi0.40Al1.60 alloy composed of three ferromagnetic phases. The maximum magnetic entropy change and refrigerant capacity of the as-cast GdNi0.40Al1.60 alloy are 8.8 J/kg K and 567 J/kg, respectively, for magnetic field change of 50 kOe. The good "table-like" magnetocaloric response makes it a promising refrigerant candidate for Ericsson cycle-based magnetic refrigeration at low temperatures. Furthermore, this type of material promises to provide a cost-effective strategy for the search of efficient magnetic refrigerants with table-like magnetocaloric feature, beneficial for Ericsson cycle.