Phase Transformations and Magnetocaloric Effect in Ni-Mn-(Co)-In Heusler Alloys

AbstractIn this work we experimentally study the magnetic properties and magnetocaloric effect (MCE) of the Ni1.73Mn1.80In0.47 and Ni1.72Co0.28Mn1.51In0.49 Heusler alloys. The direct measurements of the adiabatic temperature change ΔTad in magnetic field change to 2 T have shown that replacement of the Ni atoms with the Co atoms increases the absolute value of inverse magnetocaloric effect. Replacement of the Ni atoms on the Co atoms also increases the temperature of magnetostructural transition and Curie temperature. The maximum adiabatic temperature change of -2.4K was achieved in Ni1.72Co0.28Mn1.51In0.49 alloy at 311K (near the martensitic transformation temperature) in a field of 2 T. The magnetostructural transformation from the antiferromagnetic-like martensite to the ferromagnetic austenite phase of both compositions was found. The latent heat linked with the first-order transformation was determined by differential scanning calorimetry (DSC)