Giant low field magnetocaloric effect and field-induced metamagnetic transition in TmZn

The magnetic properties and the magnetocaloric effect (MCE) in TmZn have been studied by magnetization and heat capacity measurements. The TmZn compound exhibits a ferromagnetic state below a Curie temperature of TC=8.4K and processes a field-induced metamagnetic phase transition around and above TC. A giant reversible MCE was observed in TmZn. For a field change of 0-5T, the maximum values of magnetic entropy change (-ΔSMmax) and adiabatic temperature change (ΔTadmax) are 26.9J/kg K and 8.6K, the corresponding values of relative cooling power and refrigerant capacity are 269 and 214J/kg, respectively. Particularly, the values of -ΔSMmax reach 11.8 and 19.6J/kg K for a low field change of 0-1 and 0-2T, respectively. The present results indicate that TmZn could be a promising candidate for low temperature and low field magnetic refrigeration.