Magnetic Properties and Magnetocaloric Effect in the Ni45mn36in14co5 Alloy in the Initial State

The Ni45Mn36In14Co5 alloy was produced by the argon arc melting method. The application of a homogenization annealing process at 1173 K, followed by water quenching, resulted in the formation of a practically single-phase state. This particular state is referred to as the initial state. In the region of the structural transition, an abrupt change in magnetization is observed as the austenitic ferromagnetic phase transitions to the weakly magnetic martensitic phase. The magnetic entropy of ∆SM = -31.9 J/kg·K was obtained from thermomagnetic data in a magnetic field of 3 T. The reversible magnetocaloric effect ∆Tad = -0.7 K was observed in an alternating f = 0.2 Hz magnetic field of 1.8 T at the peak of the martensitic transformation. The maximum value observed during the initial application of the magnetic field is ∆Tad = -2.5 K. A study of the degradation of the magnetocaloric effect at the martensitic transformation temperature indicates that following 1400 cycles of magnetic field application, the ∆Tad value exhibits a 10% reduction, with a discernible ongoing trend. In conclusion, the alloy displays notable magnetocaloric effect values.