Magnetic entropy change and transport properties in Ni45Co5Mn36.6In13.4 melt-spun ribbons

Heusler alloy Ni45Co5Mn35.6In13.4 ribbons were prepared by melt spinning with different wheel linear speeds. It was found that melt spinning is an effective way to change atomic order of the crystal structure, which leads to a significant change in magnetic and transport properties as well as the martensitic transition behavior. Austenite with cubic B2 structure was confirmed for the melt-spun ribbons at room temperature. Compared to the as-prepared ingots, martensitic transition and reverse transition shift to lower temperature, and metamagnetic behavior becomes less significant due to enhanced ferromagnetic properties in martensitic phase, thus resulting in a reduced magnetic entropy change. However, an interesting transport behavior was observed in the ribbons. Under a magnetic field of 5T, a large difference in resistance appears on heating and cooling process, which is closely related to the large difference of ZFC–FC magnetization. Our analysis indicates that the change of magnetic domain configuration and the FM spin structure de-pinning under external cooling field should be responsible for the separation of ZFC–FC resistance and ZFC–FC magnetization.

► We prepared Ni45Co5Mn35.6In13.4 ribbons with two different wheel speeds.
► We examined the effect of melt spinning on atomic order and magnetic properties.
► Compared to the bulk, the martensitic transition shifts to lower temperature.
► Melt spinning technique leads to a reduced magnetic entropy change.
► A large difference of resistance appears on ZFC heating and FC cooling under 5T.