Magnetic properties and magneto-caloric performances in RECo₂B₂C (RE = Gd, Tb and Dy) compounds

We present a detailed investigation of the crystal structure, magnetism and magneto-caloric performances of RECo₂B₂C (RE = Gd, Tb and Dy) compounds. All compounds are described with a LuNi₂B₂C-type crystallographic structure (I4/mmm space group). A second-ordered paramagnetic to ferromagnetic (PM-FM) transition is observed in RECo₂B₂C compounds around their Curie temperatures (T_C) of 17.2, 5.3 and 7.7 K, and induced a considerable magneto-caloric effect (MCE) for GdCo₂B₂C, TbCo₂B₂C and DyCo₂B₂C, respectively. The magneto-caloric performances for RECo₂B₂C were characterized by the isothermal magnetic entropy (-ΔS_M ^max), temperature averaged entropy change (TEC) with three different temperature lifts (3, 5 and 10 K), and relative cooling power (RCP). The corresponding values of -ΔS_M ^max, TEC (3 K) and RCP under the magnetic field change (ΔH) of 0–5 T, are 10.34 J/kg-K, 10.23 J/kg-K, and 238.1 J/kg for GdCo₂B₂C, 18.09 J/kg-K, 17.83 J/kg-K, and 438.2 J/kg for TbCo₂B₂C, as well as 17.79 J/kg-K, 17.72 J/kg-K, and 480.1 J/kg for DyCo₂B₂C, respectively.