Magnetocaloric effect in La_1-xPr_xFe _10.7Co_0.8Si_1.5 compounds near room temperature

The magnetic properties and magnetocaloric effects in NaZn ₁₃-type La_1-xPr_xFe_10.7Co _0.8Si_1.5 compounds have been investigated. Partially replacing La with Pr leads to a small reduction in the Curie temperature T _C due to the lattice contraction, but the values of T_C for La_1-xPr_xFe_10.7Co_0.8Si_1.5 are close to room temperature. The maximum values of magnetic entropy change ΔS_m in La_1-xPr_xFe_10.7Co _0.8Si_1.5 with x 0.5 are in the range 13.5-14.6 J kg ^-1 K^-1 for a field change of 0-5 T, and correspondingly the values of the refrigerant capacity (RC) are 373-353 J kg^-1. In particular, the values of ΔS_m and RC for a low field change from 0 to 2 T are also obtained to be as high as 7.0-8.1 J kg^-1 K^-1 and 128-139 J kg^-1, respectively. No magnetic hysteresis is observed in the magnetization as a function of both the temperature and the magnetic field in the La_1-xPr_xFe _10.7Co_0.8Si_1.5 compounds. The large reversible ΔS_m and the high reversible RC for a low field change indicate that La_1-xPr_xFe_10.7Co_0.8Si _1.5 may be a promising candidate for magnetic refrigeration near room temperature.