Near room temperature magnetocaloric properties and the universal curve of MnCoGe_(1-x)CU_x

摘要

Intermetallic compounds based on MnCoGe have drawn attention due to the coupled magnetic and structural transformations and the large magnetocaloric entropy. Here, we provide a systematic comparison of experimental data under different magnetic fields with magnetic and the magnetocaloric properties. The ferromagnetic transition temperature (T_c) increases from 353.4(6) K for x = 0.01 to 363.4(4) K for x =0.04 with increasing nominal copper content. The maximum magnetic entropy change |ΔS_M| in a magnetic field change of 5 T is found to be 18.3(2) J/(kg K) with a large relative cooling power (RCP) value of 292.5(4) J/kg for x = 0.01, revealing that the present system can provide an acceptable magnetocaloric effect at a cheaper price for magnetic refrigeration materials. Making attempt to contrast a master curve for the present system, we find the experimental values of magnetic field dependence of the magnetic entropy change are consistent with a phenomenological universal curve.