Magnetocaloric effect in Gd₆Co_1.67Si₃ compound with a second-order phase transition

The magnetic properties and the magnetic entropy change \Delta S have been investigated for Gd₆Co_1.67Si₃ compounds with a second-order phase transition. The saturation moment at 5K and the Curie temperature T_C are 38.1\mu_B and 298K, respectively. The \Delta S originates from a reversible second-order magnetic transition around T_C and its value reaches 5.2J/kg\cdotK for a magnetic field change from 0 to 5T. The refrigerant capacity (RC) of Gd₆Co_1.67Si₃ are calculated by using the methods given in Refs.12 and 21, respectively, for a field change of 0--5T and its values are 310 and 440 J/kg, which is larger than those of some magnetocaloric materials with a first-order phase transition.