Magnetocaloric effect in Ni2(Mn,Cu)Ga0.84Al0.16 Heusler alloys

Polycrystalline Heusler compounds Ni2Mn0.75Cu0.25Ga0.84Al0.16, with a martensitic transition between ferromagnetic phases, and Ni2Mn0.70Cu0.30Ga0.84Al0.16, with a magnetostructural transformation, were investigated by magnetization and heat capacity measurements, both as a function of temperature and magnetic field. The compound Ni2Mn0.75Cu0.25Ga0.84Al0.16 presents a large magnetocaloric effect at a transition between magnetically aligned structures. In addition, Ni2Mn0.70Cu0.30Ga0.84Al0.16 shows very high entropy change at room temperature, although irreversible, under a magnetic field change 0?1 T. The magnetocaloric properties of the studied samples are compared with selected compounds in the literature.

Automated summary

The research revealed that two Heusler compounds, Ni2Mn0.75Cu0.25Ga0.84Al0.16 and Ni2Mn0.70Cu0.30Ga0.84Al0.16, exhibit different magnetic properties and magnetocaloric effects during magnetic field changes. Ni2Mn0.75Cu0.25Ga0.84Al0.16 shows a significant magnetocaloric effect during the transition between magnetically aligned structures, while Ni2Mn0.70Cu0.30Ga0.84Al0.16 demonstrates high entropy change at room temperature.