Impacts of first-order phase transition and phase coexistence on the universal behavior of inverse magnetocaloric effect

摘要

A systematic study of the inverse magnetocaloric effect (IMCE) in Ni_(50)Mn_(35.8)Sn_(14.2) and Pr_(0.5)Sr_(0.5)MnO_3 has been performed to understand the impacts of first-order phase transition (FOPT) and phase coexistence on the universality of the temperature-dependent magnetic entropy change, ΔS_M(T). We show that for Ni_(50)Mn_(35.8)Sn_(14.2)-a system exhibiting IMCE associated with FOPT-it is possible to construct a universal master curve to describe ΔS_m(T) in different applied fields without rescaling a temperature axis. However, the universality of IMCE does not hold for Pr_(0.5)Sr_(0.5)MnO_3-a system with coexisting ferromagnetic and antiferromagnetic phases. The proposed universal curve provides a simple method for extrapolating ΔS_m in a wide range of fields and temperatures, thus giving useful guidance to the design of magnetocaloric materials for active magnetic refrigeration technology.