Abstract
? 2022 Elsevier B.V.In this paper, the crystal structure, magnetic phase transition and magnetocaloric properties of the ErCo2-xCux (x = 0.12, 0.24, 0.36 and 0.48) compounds have been investigated in detail. All of the compounds crystallize in the C15 cubic Laves structure (MgCu2-type) with the Fd-3 m space group. The substitution of Cu for Co is accompanied by an increase of the Curie temperature Tc from 31.5 K to 68 K for x varying from 0.12 to 0.48. The nature of the magnetic phase transition, determined by the results of the Arrott plots and Landau theory, changed from a first order to a second order in the ErCo2-xCux compounds with the Cu content increasing. The isothermal entropy change -?SM is calculated according to isothermal magnetization measurements using Maxwell's relation. For an applied magnetic field change of 0–5 T, the -?SM decreased from 30 J kg?1 K?1 for x = 0.12 to 10.9 J kg?1 K?1 for x = 0.48, whereas the working temperature range became wider due to that the magnetic transition type changed from a first order to a second order, which is a benefit for the application of the magnetic refrigeration. The corresponding refrigerant capacity RC values are 270.8 J kg?1, 194.1 J kg?1, 261.8 J kg?1 and 264.8 J kg?1, respectively.
NSTL
Elsevier