Magnetic properties and large magnetic entropy change in rare earth-rich cadmium compounds of RE 4 CoCd ( RE = Tm and Ho)

The magnetic properties and the magneto-caloric effect (MCE) of the cadmium compounds Tm4CoCd and Ho4CoCd with cubic Gd4RhIn-type structure were studied. A second order magnetic phase transition from a paramagnetic (PM) to a ferromagnetic (FM) state at around the Curie temperatures of TC ∼ 4.5 and 22 K together with a large reversible MCE for Tm4CoCd and Ho4CoCd were observed, respectively. For a field change of 0–70 kOe, the values of maximum magnetic entropy change (−ΔSMmax), relative cooling power (RCP) and refrigerant capacity (RC) were evaluated to be 19.2 J/kg K, 434 J/kg and 342 J/kg for Tm4CoCd, and 18.1 J/kg K, 807 J/kg and 635 J/kg for Ho4CoCd, respectively.