Large magnetic entropy change and refrigerant capacity in rare-earth intermetallic KCuAl (R=Ho and Er) compounds

摘要

The magnetic properties and the magnetocaloric effects of RCuAl (R=Ho and Er) compounds have been investigated. Both HoCuAl and ErCuAl just undergo a second-order ferromagnetic-paramagnetic phase transition at T_C. Large reversible magnetic entropy changes (△S_M) are observed around their respective Curie temperatures due to the ferromagnetic-paramagnetic phase transition. For a field change of 0-5 T, the peak values of - △S_M of RCuAl (R = Ho and Er) compounds are 23.9 and 22.9 J kg~(-1) K~(-1) at T_C, with the values of refrigerant capacity of 393 and 321 J kg~(-1), respectively. These properties suggest that RCuAl (R=Ho and Er) compounds could be considered as attractive magnetic refrigerants working in low temperature range.