Large magnetocaloric effect in Er12Co7 compound and the enhancement of δTFWHM by Ho-substitution

Polycrystalline monoclinic Er12Co7 compound with a large magnetocaloric effect (MCE) was synthesized. The maximum values of the magnetic entropy change (ΔSM) under the field changes of 0-2 T and 0-5 T reach 10.2 J/kgK and 18.3 J/kgK, respectively. In order to gain further insight in understanding the MCE, samples with various Ho substitutions for Er were fabricated and studied. It was found that Ho-substitution makes a great impact on the magnetic properties and MCE of Er12Co7 compound. Through compositional optimization, the mixed product of Ho12Co7 and Er6Ho6Co7 with the weight ratio of 58:42 was tailored to exhibit the best MCE performance. The maximum value of ΔSM, the full width at half maximum of ΔSM-T curve and the refrigerant capacity of the mixed compound are calculated to be 16.7 J/kgK, 37.9 K and 522 J/kg, respectively.