Magnetic and magnetocaloric properties of Er(Co1−xFex)2 intermetallic compounds

Structural, magnetic and magnetocaloric properties of Er(Co1−xFex)2 (x = 0.0, 0.125 and 1) compounds are investigated. X-ray diffraction (XRD) analysis has revealed that the compounds crystallize in the C15 type Laves phase structure, with Fd-3m space group. All the samples are ferrimagnetically ordered, exhibiting a compensation point in the M(T) traces for x = 1. The substitution of Fe to Co is accompanied by an increase of the Curie temperature from 42 to 591 K, for x varying from 0 to 1. Magnetocaloric effect (MCE) is anticipated according to the Maxwell relation based on isothermal magnetization measurements. A maximum |ΔSM| value is found decreasing from 21 J.kg−1.K−1for x = 0 to 1.5 J.kg−1.K−1 for x = 1 under an applied magnetic field change of 0-5 T. This decrease is accompanied by a change in the nature of the magnetic transition which becomes 2nd order when substituting Fe to Co.