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 TC = 50, 17, and 10 K 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.