Magnetic and magnetocaloric properties in melt-spun and annealed Ni42.7Mn40.8Co5.2Sn11.3 ribbons

The Ni42.7Mn40.8Co5.2Sn11.3 ribbons were prepared by melt spinning. After heat treatment, the martensitic transformation temperature and Curie temperature of austenite of the annealed ribbons increased remarkably. Inverse and direct magnetocaloric properties were investigated in the melt-spun and annealed ribbons. The effective refrigerant capacities for these ribbons were discussed in this paper.

Research highlightsIn this paper, the Ni42.7Mn40.8Co5.2Sn11.3 ribbons were prepared by melt spinning and the magnetic and magnetocaloric properties for the melt-spun and annealed ribbons were investigated. After heat treatment, the martensitic transformation (MT) temperature and Curie temperature of austenite TCA increased remarkably. Enhanced magnetization and obvious metamagnetic behavior are also observed in the annealed ribbons. Large near-room-temperature magnetocaloric effects can be obtained in these ribbons. The values of isothermal magnetic entropy change ΔSM around MT and TCA of the annealed ribbons are larger than those of melt-spun ones. However, the effective refrigerant capacities RCeff around MT retains almost unchanged for these ribbons, owing to the large hysteretic losses associated with the field-induced metamagnetic transition in the annealed ribbons. Around TCA, RCeff increases notably after heat treatment and is much larger than that around MT.