Effects of Y doping on the magnetic properties and magnetocaloric effect of CeFe₂

The magnetic properties and electronic structure of single phase cubic Laves Ce 1− x Y x Fe 2 compounds with x ≤ 0.25 are analysed by correlating magnetic measurements with band structure calculations. The Y substitution for Ce stabilizes a ferrimagnetic order in all investigated samples, as indicated by the increase of the spontaneous magnetization values with the decrease of Ce content. The band structure calculations yield negative magnetic moments for the Ce and Y atoms, hence an antiferromagnetic coupling to the Fe magnetic moments. All samples show a second order magnetic phase transition and a roughly linear increase of the transition Curie temperature with Y concentration from 247 K for x = 0.1 to 330 K for x = 0.25. The magnetocaloric effect around the magnetic transition temperature was also investigated and although the maximum value of the magnetic entropy change decreases with increasing yttrium content, large RCP(S) values were obtained for all samples due to the broad ∣Δ S m ∣ peaks.