Magnetic transition and large reversible magnetocaloric effect in EuCu_1.75P₂ compound

The magnetocaloric effect (MCE) in EuCu_1.75P₂ compound is studied by the magnetization and heat capacity measurements. Magnetization and modified Arrott plots indicate that the compound undergoes a second-order phase transition at T_C～51 K. A large reversible MCE is observed around T_C. The values of maximum magnetic entropy change (-ΔS_M^max) reach 5.6 J·kg^-1·K^-1 and 13.3 J·kg^-1·K^-1 for the field change of 2 T and 7 T, respectively, with no obvious hysteresis loss in the vicinity of Curie temperature. The corresponding maximum adiabatic temperature changes (ΔT_ad^max) are evaluated to be 2.1 K and 5.0 K. The magnetic transition and the origin of large MCE in EuCu_1.75P₂ are also discussed.