Magnetic properties and magnetic entropy changes of MRE2Co7 compounds

（La0.5Ce0.5）2Co7 and（Ce0.65Pr0.35）2Co7 compounds for magnetic refrigeration were studied by X-ray diffraction, ac susceptibility and isothermal magnetization measurements. X-ray powder diffraction shows that all the compounds have hexagonal Ce2Ni7-type structure. The Curie temperatures（TC） are 258 K and 222 K for（La0.5Ce0.5）2Co7 and（Ce0.65Pr0.35）2Co7 compounds, respectively. High coercivities（HC） of about 1.74 and 6.61 k Oe at 5 K with a smooth demagnetization curves were obtained for the（La0.5Ce0.5）2Co7 and（Ce0.65Pr0.35）2Co7 compounds, respectively. For an applied field change from 0 to 50 k Oe, the maximum（？？SM） for（La0.5Ce0.5）2Co7 and（Ce0.65Pr0.35）2Co7 compounds are 0.52 and 0.67 J/（kg K）, respectively.