Magnetic properties and magnetocaloric effect of Sc2CoSi2-type Gd2CoSi2 and Gd2CoGe2 compounds

The Sc2CoSi2-type compounds Gd2CoSi2 and Gd2CoGe2 show a ferromagnetic-type transition at 213 and 143 K, respectively, and Gd2CoSi2 has low-temperature transition at ∼30 K. Magnetocaloric effect of the compounds is studied in terms of isothermal magnetic entropy change (−ΔSm) and −ΔSm reaches the maximum value of ∼3.0 J/kg K at 215 K for Gd2CoSi2 and ∼5.1 J/kg K at 145 K for Gd2CoGe2. The novel Hf3Ni2Si3-type Gd3Co2Ge3 compound shows antiferromagnetic-type transition at 44 K.