Enhanced magnetocaloric application potential of Co-substituted rare-earth Laves-phase TbMn2 compounds

Rare-earth Laves-phase compounds are promising magnetocaloric materials due to their large localized magnetic moment below the Curie temperature. In this work, the effects of Co on the microstructure, Curie temperature, and magnetocaloric properties of the rare-earth Laves-phase TbMn 2- x Co x ( x = 0, 0.5, 1) compounds are systematically examined. Replacing Mn with Co results in a higher Curie temperature and simultaneously enhances mechanical and magnetocaloric properties. Magnetic measurements confirm that the Curie temperatures for x = 0.5 and 1 samples are 160 K and 238 K, respectively, significantly higher than the ∼50 K observed in the Co-free sample. The Ab initio simulation results and reduction of cracks and holes confirm the improved mechanical properties with increasing Co content. Most notably, large magnetocaloric effects near the Curie temperature are obtained, including magnetic entropy changes of 6.1 and 4.6 J kg -1 ·K -1 , and effective refrigerant capacities of 327.0 and 291.6 J kg -1 under a field change of Δ μ 0 H = 0-5 T for x = 0.5 and 1 samples, respectively. These results suggest that the studied samples are promising materials for magnetic refrigeration.