Magnetocaloric effect in ErCo₂ compound

The ErCo ₂ compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/(kg \cdot K) and its refrigerant capacity achieves 291 J/kg at 0--5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo ₂ compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below T_C.