Comparative study of the magnetocaloric effect in multiphase GdNiAl alloys: Single peak versus table-like profile in magnetic entropy changes

Abstract This paper presents a comparative analysis of the magnetic and magnetocaloric properties of multiphase Gd 28 Ni 24 Al 48 and Gd 33 Ni 13 Al 54 alloys. Both as-cast alloys are composed of GdNiAl 2 , GdNiAl and Ni-substituted GdAl 2 ferromagnetic phases. The component ferromagnetic phases have closely adjacent ordering temperatures near 40 K, resulting in a reasonably large magnetic entropy change ( ΔS M ) for the Gd 28 Ni 24 Al 48 alloy, while the widened ferromagnetic phase transitions contribute to the “table-like” ΔS M profile and considerable refrigerant capacity ( RC ) in the Gd 33 Ni 13 Al 54 alloy. The above difference is principally due to the influence of the Ni Al substitution on the transition temperatures of GdNiAl and GdAl 2 phases. The − ΔS M s and RC s of 14.5 J/kgK, 500 J/kg and 9.2 K/kgK, 591 J/kg were obtained, for a 50 kOe field change, for the Gd 28 Ni 24 Al 48 and Gd 33 Ni 13 Al 54 alloys, respectively. The plateau-shaped − ΔS M and considerable RC qualify the Gd 33 Ni 13 Al 54 alloy as a competitive refrigerant candidate for regenerative Ericsson cycle based magnetic refrigeration at low temperatures.