Influence of Ti substitution on magnetic and magnetocaloric properties of Pr 2 Fe 17-x Ti x intermetallic compounds

The structural, magnetic, and magnetocaloric properties of the Pr 2 Fe 17-x Ti x ( x = 0, 0.2, 0.4, 0.6) intermetallic compounds prepared by the arc-melting process were investigated. X-ray analyses indicated that all samples are single phase with the rhombohedral Th 2 Zn 17 -type structure. The unit-cell volume was determined to increase with the increasing Ti content. The magnetic measurements revealed that the Curie temperature increases with Ti content from 286 K for x = 0 to 337 K for x = 0.6. The maximum value of |ΔSm| tends to decrease from 5.63 J/kg.K for x = 0 to 4.28 J/kg.K for x = 0.6 with increasing Ti content at 5 T magnetic field change. At the same magnetic field change, the relative cooling power (RCP) ranges from 425.17 J/Kg for x = 0 to 385.62 J/Kg for x = 0.6. The critical exponents ( β , γ , and δ ) determined from magnetocaloric data for x < 0.2 belong to mean-field model with long-range ferromagnetic interaction. A small deviation in the critical exponents of γ and δ for x > 0.4 samples was attributed to inhomogeneous magnetic state of the samples. From the phase analysis, it was concluded that all samples showed a second-order magnetic phase transition.