Magnetic properties and magneto-caloric effect in pseudo-binary intermetallic (Ce,R)2Fe17 compounds (R = Y, Pr and Dy)

We have synthesized three pseudo-binary (Ce,R)2Fe17 intermetallic alloys, where cerium has been partially substituted by R = Y, Pr and Dy, with the aim of tuning the Curie temperature (between 253 and 273 K) for obtaining the maximum magneto-caloric response of the alloys just below room temperature. The analysis of the x-ray powder diffraction patterns show that the three samples crystallize in the rhombohedral Th2Zn17-type crystal structure (space group R 3 ¯ m ). We report the temperature dependence of the isothermal magnetic entropy change, |ΔSM|(T), the magnetic field dependence of its maximum value, |ΔSMmax|(H), and the relative cooling power around the second-order magnetic transition for magnetic field changes μ0ΔHmax = 5 T. The collapse of the normalized ΔSM(θ)/ΔSMmax vs. temperature (where θ is a rescaled temperature) into a single master curve allows the extrapolation of |ΔSM|(T) curves for higher magnetic field changes, and/or the estimation of the temperature dependence of the magnetic entropy for other 2:17 pseudo-binary compounds. The lower values of |ΔSMmax| compared with those of the R2Fe17 compounds with R = Pr or Nd are explained in terms of the decrease of the saturation magnetization. The magnetic field dependence of the |ΔSMmax| indicates that only Pr1.5Ce0.5Fe17 alloy roughly follows a mean-field behaviour.