Controllable spin-glass behavior and large magnetocaloric effect in Gd-Ni-Al bulk metallic glasses

Glass-forming ability, spin-glass (SG) behavior, and magnetocaloric effect in Gd55NixAl45-x (x = 15, 20, 25, 30) metallic alloys were investigated. A ferromagnetic SG behavior was observed for glassy ribbons with compositions of x = 15, 20, and 25, but it disappeared for that of x = 30. Furthermore, the maximum magnetic entropy change (-Delta S-m(max)) increased with the increasing Ni/Al-ratio while the decrease of full width at half -Delta S-m(max) was almost negligible. Accordingly, -Delta S-m(max) of 9.25 J kg(-1) K-1, adiabatic temperature change of 4.3 K and refrigeration capacity of 851 J kg(-1) under 50 kOe were obtained for Gd55Ni30Al15 glassy alloy. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4738778]