Magnetocaloric properties of DyCo2−xGax alloys

The influence of the substitution of Ga atoms for Co atoms in DyCo2 compounds on magnetocaloric properties has been investigated. A series of DyCo2−xGax alloys with x = 0 , 0.03, 0.06, 0.1, 0.15, and 0.2 was prepared by the arc-melting method for this investigation. Experimental results revealed that the Ga substitution for Co in DyCo2 can form a single phase with the cubic Laves phase structure up to x = 0.2 . As the Ga content x increases, the lattice parameter and the Curie temperature T c increases from 143 to 196 K linearly. The maximum magnetic entropy changes | Δ S M , max | in a low field change of 0–1.5 T, increasing from 8.24 to 10.61 J/K kg when the Ga content x increases from 0 to 0.03, but decreasing gradually to 3.51 J/K kg as the Ga content further increases to x = 0.2 . All the samples show a relatively large magnetic entropy change with very small hysteresis loss.