Magnetic properties and magnetocaloric effects in R₆Co₂Si₃ compounds with R = Nd and Tb

Magnetic properties and magnetocaloric effects of the R₆Co₂Si₃ compounds with R = Nd and Tb have been investigated by magnetization measurement. The Curie temperature and the saturation moment at 5 K for R₆Co₂Si₃ with R = Nd and Tb are determined to be 84.5 and 186.9 K, and 11.3 and 39.5 μ_B, respectively. The magnetic entropy change ΔS_m of R₆Co₂Si₃ with R = Nd and Tb, which originates from a reversible second-order magnetic transition around T_C, are obtained to be respectively 5.3 and 6.8 J/(kg K) for a magnetic field change from 0 to 5 T. A high refrigerant capacity for Tb₆Co₂Si₃ is found to be 441 J/kg for a field change of 0-5 T, which is due to a broad distribution of the ΔS_m peak.