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A single-phased DyCo3B2 compound has been prepared by an arc-melting method. The magnetic properties and magnetocaloric effect (MCE) have been studied by the magnetization and heat capacity measurements. The compound undergoes a magnetic Co-Co sublattice ordering at ∼150 K, and a second magnetic Dy-Dy sublattice ordering transition at 22 K. Magnetization and modified Arrott plots indicate that DyCo3B2 compound undergoes a second-order phase transition at ∼22 K. A large reversible magnetocaloric effect has been observed around Dy-Dy sublattice ordering temperature. The values of maximum magnetic entropy change (−ΔSMmax) reach 7.4 and 15.1 J kg−1 K−1 for the field change of 2 and 7 T with no obvious hysteresis loss around 25 K; the corresponding values of maximum adiabatic temperature changes (ΔTadmax) are evaluated to be 6.4 and 13.8 K, respectively. The large reversible ΔSMmax and ΔTadmax, as well as considerable relative cooling power, make DyCo3B2 compound a suitable candidate for low temperature magnetic refrigeration.

Magnetic Properties and Magnetocaloric Effect in GdCo 3 B 2 Compound. -The title compound is prepared by arc melting of stoichiometric amounts of the elements followed by annealing at 1073 K for one week. The samples are characterized by XRD, magnetization, and specific heat measurements. The maximum magnetic entropy changes reach 5.0 and 11.6 Jkg -1 K -1 for a field change of 2 and 7 T with no obvious hysteresis loss around 56 K, respectively. The corresponding maximum adiabatic temperature changes are 2.8 and 6.4 K. The reversible magnetocaloric effect is related to a second-order Gd-Gd sublattice magnetic phase transition. -(LI*, L.; NISHIMURA, K.; IGAWA, H.; HUO, D.; J. Alloys Compd. 509 (2011) 11, 4198-4200, http://dx.