Large magnetocaloric effect with a wide working temperature span in the R2CoGa3 (R=Gd, Dy, and Ho) compounds.

We investigate magnetic properties and magnetocaloric effects of R₂CoGa₃ (R=Gd, Dy, and Ho) compounds. It is found that all the compounds are ferromagnetic with the Curie temperatures of T_C=50, 17, and 10K for R=Gd, Dy, and Ho, respectively. The R₂CoGa₃ have large magnetic entropy change (ΔS) that arise from the second-order ferromagnetic-to-paramagnetic phase transition. The maximum values of ΔS are found to be –12.6, –10.8, and –13.8 J/kg K with corresponding refrigerant capacity values of 382, 252, and 287 J/kg for a magnetic field change of 0–50 kOe, respectively. The large ΔS values with little or no hysteresis losses as well as wide working temperature spans imply that the R₂CoGa₃ compounds may serve as promising candidates for magnetic refrigeration. [ABSTRACT FROM AUTHOR]