Theoretical work on magnetocaloric effect in La_(0.75)Ca_(0.25)MnO_(3)

摘要

In this work,a phenomenological model is applied to describe the magnetocaloric effect for the La_(0.75)Ca_(0.25)MnO_(3)system near a second-order phase transition from a ferromagnetic to a paramagnetic state.Based on this model,it can predict the values of the magnetocaloric properties from calculation of magnetization as a function of temperature under different external magnetic fields.The magnetic entropy change reaches a peak of about 5.39 J/(kg·K)at 257 K upon 4 T applied field variation.TheΔSM distribution is much more uniform than that of gadolinium,which is desirable for an Ericson-cycle magnetic refrigerator.