Large magnetocaloric effect in re-entrant ferromagnet PrMn1.4Fe0.6Ge2

Abstract

Magnetocaloric effects (MCE) at multiple magnetic phase transition temperatures in PrMn1.4Fe0.6Ge2 were investigated by heat capacity and magnetization measurements. PrMn1.4Fe0.6Ge2 is of a re-entrant ferromagnet and performs multiple magnetic phase transitions in the temperature range from 5 to 340 K. A large magnetic entropy change (−ΔSM) 8.2 J/kg K and adiabatic temperature change (ΔTad) 4.8 K are observed for a field change of 0–1.5 T around 25.5 K, associated with the field-induced first order magnetic phase transition (FOMT) from the antiferromagnetic to the ferromagnetic state with an additional Pr magnetic contribution. These results suggest that a re-entrant ferromagnet is probably promising candidate as working material in the hydrogen and nature gas liquefaction temperature range magnetic refrigeration technology. © 2010, Elsevier Ltd.